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OBS501 Smart Turbidity Meter

1. 1 Remove the stop screw in the OBS501 housing at the end of the shutter wiper slot 2 Remove the 4 40 flat head screw and copper plate to expose the drive shaft access port Figure 8 6 3 Insert a slot screw driver 2 5 mm 0 1 in wide blade into the access port Figure 3 7 4 Engage the end of the drive shaft and then rotate clockwise until the shutter is free Figure 8 7 and Figure 8 8 CAUTION Keep track of all of the components Figure 8 9 5 Reassemble by reversing the steps Remove 4 40 flat head screw Figure 8 6 Remove the screw 29 OBS501 Smart Turbidity Meter with ClearSensor Technology Drive shaft access port Figure 8 8 Shutter disassembled Shutter dopper plate NU ee nut spacer a Figure 8 9 Shutter components 30 User Manual 9 Maintenance WARNING WARNING There is a biocide chamber in the slider that is refillable The default biocide from the factory is copper braid The braid will last for many years but it can be replaced as desired Other solid biocides can be placed in the chamber To be effective over time the biocide should be slow to dissolve The OBS501 should be sent in for service seal shaft and nut replacement after 2 years or 70 000 cycles of the shutter whichever occurs first The sensor has a cycle count and a moisture alarm in the data string SDI 12 and RS 232 only If the seals are not replaced the sensor will eventually leak and potentially
2. Level Fow Quilty J 247 2474 Conductvity and Temperature Probe 0 05510 Ditsolvad Oxygen Probe J CSS11 Dissolved Oxygen Probe 3 C5512 Cisscived Oxygen Probe Ll lt J 05525 ISFET pH Probe J 05526 ESET qu Probe J CSSA7A Conductivity and Temperature Probe I CSIM11 ORP Probe 151 M11 089 J CSIMLI pH Probe ISI M11 pH tr Stu Mat Paramoter TROLL 9000 J 085 3 Turtedty Moretor 085 3 085300 Turtedty Sensor a J 085500 Smart Turbidity Mater 501 12 lt lt Backscatter Turtidity Tub_35 rou J Offset Catcutaton x E J 51 12 Muttipeobe Gidescatter Turtidity Turb_ss may Calicdabons A Control T ave imc 7 ra lt a Wet Dry Condition wo_085 cortesi 501 12 Address 0 9 A Z cr a 2 0 lt 095500 Smart Turtadity Mater Tha sensor file wil configure thal Measure sensor Every Scan lt a temperature measurement and ql fe Backscatter Turbadity units are Sidescatter Turtety units are Temperature units are Deg C 085509 Smart Turteday Meter SDI 12 Thes senser file wil configure the datalogger such that it wil retneve backscatter turbidity sidescatter turbr ity im oe rosent and cenditien Osdry 1mwet of the mater from the 085500 Backscatter TurbiSity units are FBU Formann Backscatter 6 After selecting the sensor click at the left of the screen on Wiring Diagram to see how the sensor is to be wired to the datalogger The wiring diagram can be printed out now or after more sensors are adde
3. 645 mm 1 1b pound weight 0 454 kg Length 1 in inch 25 4 mm Pressure 1 psi Ib in 68 95 mb 1 ft foot 304 8 mm 1 yard 0 914 m Volume 1 UK pint 568 3 ml 1 mile 1 609 km 1 UK gallon 4 546 litres 1 US gallon 3 785 litres 1 oz ounce 28 35 g In addition while most of the information in the manual is correct for all countries certain information is specific to the North American market and so may not be applicable to European users Differences include the U S standard external power supply details where some information for example the AC transformer input voltage will not be applicable for British European use Please note however that when a power supply adapter is ordered it will be suitable for use in your country Reference to some radio transmitters digital cell phones and aerials may also not be applicable according to your locality Some brackets shields and enclosure options including wiring are not sold as standard items in the European market in some cases alternatives are offered Details of the alternatives will be covered in separate manuals Part numbers prefixed with a symbol are special order parts for use with non EU variants or for special installations Please quote the full part number with the when ordering Recycling information At the end of this products life it should not be put in commercial or domestic refuse but sent for recycling Any batteries contained w
4. CHR 62 is gt Now the data comes ending with a carriage return CHR 13 Split the ASCII string into numeric variables Appendix B Example Programs B 4 CR1000 Analogue Program Although this is a CR1000 program other CRBasic dataloggers are programmed similarly CR1000 Series Datalogger 0BS501_analogue_08M CR1 for the CR1000 wiring Green to 1H Brown to 1L Red to SW12 Black to Grnd Blue to C1 and White to C2 Declare Public Variables Public PTemp batt_volt Public Results 2 Alias Results 1 obs Alias Results 2 ss Units obs NTU Units ss NTU DataTable 0BS501_analogue 1 1 DataInterval 0 3 min 10 Minimum 1 batt_volt FP2 0 False Sample 1 PTemp FP2 Sample 1 obs FP2 Sample 1 ss FP2 EndTable Main Program BeginProg Scan 30 sec 3 0 PanelTemp PTemp 250 Battery batt_volt PortSet 1 1 blue wire drive high to open shutter PortSet 2 0 white wire selects obs 0 or ss 1 Delay 0 9500 msec 6 secs shutter open 3 5 secs VoltDiff obs 1 0 1 1 0 60Hz 1 0 1 mV 1 TU PortSet 2 1 white wire to 5 volts for ss meas Delay 0 800 msec wait until meas is done VoltDiff ss 1 0 1 1 0 _60Hz 1 0 PortSet 1 0 blue wire drive low to close shutter CallTable 0BS501_analogue NextScan EndProg Appendix B Example Programs B 5 Examples for High Sediment Loads B 5 1 Normally Open CR1000 Example CR1000 Series Datalogger 0BS501 normally open In normally o
5. Open CRBasic Editor Click File Open Assuming the default paths were used when Short Cut was installed navigate to C CampbellSci SCWin folder The file of interest has a CR6 CR2 CR1 CR8 CR3 or CR5 extension for CR6 CR200 X CR1000 CR800 CR3000 or CR5000 dataloggers respectively Select the file and click Open Immediately save the file in a folder different from Campbellsci SCWin or save the file with a different file name Once the file is edited with CRBasic Editor Short Cut can no longer be used to edit the datalogger program Change the name of the program file or move it or Short Cut may overwrite it next time it is used 5 6 The program can now be edited saved and sent to the datalogger Import wiring information to the program by opening the associated DEF file Copy and paste the section beginning with heading Wiring for Appendix A Importing Short Cut Code A 1 2 Edlog NOTE CRXXX into the CRBasic program usually at the head of the file After pasting edit the information such that a character single quotation mark begins each line This character instructs the datalogger compiler to ignore the line when compiling the datalogger code Use the following procedure to import Short Cut code into the Edlog program editor CR10 X CR500 CR510 and CR23X dataloggers 1 Create the Short Cut program following the procedure in Section 4 Qu
6. Units wet_dry YesNo Define Data Tables DataTable Test 1 1000 DataInterval 0 5 Min 10 Sample 1 turb_bs FP2 Sample 1 turb_ss FP2 EndTable Main Program BeginProg SDI12Recorder obsDatOpen 1 0 M3 1 0 Start with shutter open Scan 1 Min 0 0 TimeCounter TimeCounter 1 Wipe at a slower interval than the scan interval If TimeCounter gt 60 Then This value 60 will wipe once every 60 scan intervals 60 minutes in this case SDI12Recorder obsDatClose 1 0 M7 1 0 SDI12Recorder obsDatOpen 1 0 M3 1 0 TimeCounter EndIf Read OBS5 1 each scan interval SDI12Recorder 0BS501 1 0 M4 1 0 Measure without moving the wiper Call Output Tables CallTable Test NextScan EndProg Appendix B Example Programs B 5 2 Cycle Shutter Wiper for Each Measurement CR1000 Program The following CRBasic program will e Open the shutter if closed then make a measurement e Make a measurement if open then close Shutter wiper cycles will be cut by 50 This will reduce wear and power consumption 50 but still leave the optics shuttered 50 of the time CR1000 Series Datalogger 0BS501 cycle shutter each measurement Declare Public Variables Public 0BS501 4 Public obsDatOpen 4 obsDatClose 4 Public Open Declare Other Variables Alias 0BS501 1 turb_bs Alias 0BS501 2 turb_ss Alias 0BS501 3 tempC_0BS501 Alias 0BS501 4 wet_dry Alias obsDatOpen 1 Open_counts Full mov
7. 3 5 or 7 prompt key in the control port number where the OBS501 is connected and press lt enter gt The response Entering SDI12 Terminal indicates that the OBS501 is ready to accept SDI 12 commands 5 To query the OBS501 for its current SDI 12 address key in lt enter gt and the OBS501 will respond with its SDI 12 address If no characters are typed within 60 seconds the mode is exited In that case simply enter the command SDI12 again press lt enter gt and key in the correct control port number when prompted 6 To change the SDI 12 address key in aAb lt enter gt where a is the current address from the above step and b is the new address see Figure D 2 The OBS501 will change its address and the datalogger will respond with the new address To exit SDI 12 transparent mode select the Close Terminal button D 3 Appendix D SDI 12 Sensor Support D 4 Terminal Emulator Edit Terminal Open CR1000 gt SDI12 Enter Cx Port 1 3 5 or 7 1 Entering SDI12 Terminal 21 Select Device Y All Caps Mode C Pause Figure D 2 CR1000 example of using the SDI 12 transparent mode to change the SDI 12 address from 3 to 1 Sensor is connected to control port 1 D 2 3 CR10X Datalogger Example 1 2 Connect an OBS501 to the CR10 X see Table 7 3 Download a datalogger program that contains the SDI 12 Recorder P105 instruction with valid entries for each parameter Make sure that parameter 3 of the P10
8. 4 CR1000 Analogue Program p B 4 for an example of using these CRBasic instructions 7 4 3 Edlog Programming Our CR500 CR510 CR10 X and CR23X dataloggers are programmed with Edlog These dataloggers use Instruction 105 SD 2Recorder to read the OBS501 Your datalogger manual has a detailed explanation of Instruction 105 Note that Edlog only allocates one input location for Instruction 105 Multiple input locations are required The additional input location needs to be inserted manually using the Input Location Editor To get into the Input Location Editor select Edit Input Labels or press the F5 key Once in the Input Location Editor follow these steps 1 Choose Edit Insert Block 2 After the Insert Block dialog box appears type in a base name for the input locations Each input location will have the base name with an underscore and a consecutive number 3 Inthe Start Address field type in the number of the first input location 4 Inthe Number of InLocs field type in number of input locations needed and select OK User Manual 7 5 Mounting Suggestions CAUTION Maximum depth for the OBS501 housing is 100 metres Schemes for mounting the OBS501 will vary with applications however the same basic precautions should be followed to ensure the unit is able to make a good measurement and that it is not lost or damaged e The most important general precaution is to orient the unit so that the OBS sensor looks
9. Manual COM320 Radio El Sensor CRS451 Series CS120 CS125 CS140 CS450 Series CS451 Series CS650 Series EC100 TGA100A TGA200 E Unknown Unknown E Wireless Sensor CWB100 CWS220 CWS655 CWS900 OBS500 OBS_500 gt OBS_500 gt 1 serial number sdi 12 address vesel drive final stage hardware soft_gain obs amp iso obs raw iso_90deg raw boot os amp coef sig OBS_500 gt H 1 read raw obs Communication Port COM24 Use IP Connection Baud Rate Y All Caps window position count fits counts obs coef 5 data 7 iso coef 4 data 7 offsets obs iso 0 caro 0 E Echo Input gain obs iso 22 002662 0 023437 1 000000 1 000000 042858 volts 0 018457 volts c o Oxbef7 0x44de 0x9018 90deg volts boot sig os sig Pause StartExport SendFile Figure 7 2 Terminal Mode using 1 and H commands Table 7 2 RS 232 Terminal Commands Terminal Commands Values Returned 1 Identify Serial Number SDI 12 address etc 2 Open Wiper 3 Close Wiper Command to open wiper started please wait Wiper now open average current was xxx mA Command to close wiper started please wait Wiper now closed average current was xxx mA OBS501 Smart Turbidity Meter with ClearSensor Technology 7 2 2 Setting Editor Tab DevConfig allows you to change the configuration of the OBS501 by sel
10. WD_OBS Units BattV Volts Units PTemp_C Deg C Units Turb_BS FBU Units Turb_SS FNU Units Temp_C Deg C Units WD_OBS unitless Define Data Tables DataTable Table1 True 1 DataInterval 60 Min 10 Sample 1 Turb_BS FP2 Sample 1 Turb_SS FP2 Sample 1 Temp_C FP2 Sample 1 WD_OBS FP2 EndTable DataTable Table2 True 1 DataInterval 0 1440 Min 10 Minimum 1 BattV FP2 False False EndTable Main Program BeginProg Main Scan Scan 5 Sec 1 0 Default Datalogger Battery Voltage measurement Battv Battery BattV Default Wiring Panel Temperature measurement PTemp_C PanelTemp PTemp_C 60 0BS501 Smart Turbidity Meter SDI 12 measurements Turb_BS SDI12Recorder 0BS501 C1 0 M 1 0 Call Data Tables and Store Data CallTable Table1 CallTable Table2 NextScan EndProg Turb_SS Temp_C and WD_OBS Appendix B Example Programs B 2 CR1000 SDI 12 Program B 2 CR1000 Series Datalogger Declare Public Variables Public SDI 4 Declare Other Variables Alias SDI 1 OBS Alias SDI 2 SS Alias SDI 3 Temp Alias SDI 4 WetDry Define Data Tables DataTable Test 1 1000 DataInterval 0 15 Min 10 Sample 1 0BS FP2 Sample 1 SS FP2 Sample 1 Temp FP2 Sample 1 WetDry FP2 EndTable Main Program BeginProg Scan 30 Sec 0 0 SDI12Recorder SDI 1 0 M 1 0 0 Call Output Tables CallTable Test NextScan EndProg Appendix B Example Programs B 3 CR1000 RS 232 Pr
11. and add about 10 cc of water from the suspender tub to the teacup and mix the water and sediment into a smooth slurry with the teaspoon Add the sediment slurry to the tub and rinse the teacup and spoon with tub water to get all the material into the suspender Turn the suspender on and let it run for 10 minutes or until the OBS signal stabilizes Take averages of signals with the computer or datalogger and enter them on the calibration log sheet Calculate the sediment weight increment as follows Wi 2500 mg 4000 Vx where Wi the incremental weight of sediment and Vx the average output signal from step 6 The resulting weight gives the amount of sediment to add in order to have evenly spaced calibration points Add enough additional sediment to get one full increment of sediment Wi 5 Repeat steps 4 5 and 6 Repeat step 8 until five full increments of sediment have been added or until the OBS signals exceed the output range Perform 3 order polynomial regressions on the data to get the coefficients for converting OBS output to SSC in High Sediment Loads and Sandy Sediments Sites with high sediment loads and large sand grains can be problematic for the shutter and it s motor The recommendations provided in this section should help reduce these problems Typically sites with high biological growth have relatively low sediment loads Run the OBS501 in a normally open mode For example close then open the
12. into clear water without reflective surfaces This includes any object such as a mounting structure a streambed or sidewalls The backscatter sensor in the OBS501 can see to a distance of about 50 cm 20 in in very clean water at angles ranging from 125 to 170 The sidescatter SS sensor can only see to about 5 cm 2 in at 90 e The sensor has ambient light rejection features but it is still best to orient it away from the influence of direct sunlight Shading may be required in some installations to totally protect from sunlight interference e Nearly all exposed parts of the instrument are made of Delrin a strong but soft plastic Always pad the parts of the OBS501 housing that will contact metal or other hard objects with electrical tape or neoprene e Mounting inside the end of a PVC pipe is a convenient way to provide structure and protection for deployments The OBS501 will fit inside a 2 in schedule 40 PVC pipe The most convenient means for mounting the unit to a frame or wire is to use large high strength nylon cable ties 7 6 mm 0 3 in width or stainless steel hose clamps First cover the area s to be clamped with tape or 2 mm 1 16 in neoprene sheet Clamp the unit to the mounting frame or wire using the padded area Do not tighten the hose clamps more than is necessary to produce a firm grip Overtightening may crack the pressure housing and cause a leak Use spacer blocks when necessary to prevent chaf
13. is shipped on the Campbell Scientific ResourceDVD included with the OBS501 NOTE The OBS501 is supported in DevConfig version 1 16 or higher E J Device Configuration Utility 2 00 File Options Help 085500 Send Os OBS500 COM220 In order to connect to the OBS500 you must connect the probe s RX TX and ground leads to a serial port on your computer This is most easily done by using the OBS500 test cable Device Type AVW200 Series SMPX CR800 Series CR9000x S120 CS650 Series CWB 100 PC Serial Port comi es Baud Rate Figure 7 1 Device Configuration Utility After installing DevConfig select the OBS500 in the Device Type selection Select the correct PC Serial Port and then click Connect see Figure 7 1 7 2 1 Terminal Tab The Terminal tab can be used to verify the setup of the OBS501 Select the Terminal tab Click in the Terminal window and select the Enter key several times This will wake up the RS 232 mode of the sensor Once successfully connected you will see an OBS 500 gt prompt Figure 7 2 shows DevConfig after pressing l one to identify the OBS501 By default the OBS501 is in the SDI 12 mode for communication Once in the RS 232 mode if there is no communication for 20 seconds the sensor will return to the SDI 12 mode Device Type File Backup Options Help Settings Editor Send 0S Terminal User
14. maximum ss median ss mean ss standard deviation ss minimum ss maximum total open close count open wiper position count open max current count open timeout count close wiper position count close max current count close timeout count With the SDI 12 concurrent measurements aCx the datalogger does not request the data until the next interval hits For example if you have a 30 minute interval you will not see the data for 30 minutes There is not an equivalent M command to the aC1 aC5 and aC8 commands since the M command is limited to nine returned values As the measurement data is transferred between the probe and the datalogger digitally there are no offset errors incurred with increasing cable length as seen with analogue sensors However with increasing cable length there is still a point 21 OBS501 Smart Turbidity Meter with ClearSensor Technology 22 when the digital communications will break down resulting in either no response or excessive SDI 12 retries and incorrect data due to noise problems In these circumstances use the aMC command to do a cyclic redundancy check CRC 8 5 1 1 Measuring Multiple SDI 12 Sensors 8 5 2 RS 232 Up to ten OBS501s or other SDI 12 sensors can be connected to a single datalogger control port Each SDI 12 device must have a unique SDI 12 address of 0 and 9 A to Z ora to z See Appendix D SDI 12 Sensor Support p D 1 for more information RS 232 measuremen
15. on the relative concentrations of coloured sediments Appendix D SDI 12 Sensor Support 1 0 Calcite 0 8 Andesine o Montmorillonite Labradorite 865 nm Reflectivity e Actinolite e a 0 2 Hornblende Magnetite 0 0 10 4 6 8 Munzell Value 0 Black 10 White Figure E 5 Infrared reflectivity of minerals as a function of 10 Munzell Value E 6 Water Colour Some OBS users have been concerned that colour from dissolved substances in water samples not coloured particles as discussed in Appendix E 5 IR Reflectivity Sediment Colour p E 4 produces erroneously low turbidity measurements Although organic and inorganic IR absorbing dissolved matter has visible colour its effect on turbidity measurements is small unless the coloured compounds are strongly absorbing at the sensor wavelength 850 nm and are present in high concentrations Only effluents from mine tailings produce enough colour to absorb measurable IR In river estuary and ocean environments concentrations of coloured materials are too low by at least a factor of ten to produce significant errors E 7 Bubbles and Plankton Although bubbles efficiently scatter light monitoring in most natural environments shows that OBS signals are not strongly affected by bubbles The sidescatter measurement may be more affected Bubbles and quartz particles backscatter nearly the same amount of light to within a factor of approximately four but
16. other optical turbidity monitors the response depends on the size the composition and the shape of suspended particles For this reason for monitoring concentrations 17 OBS501 Smart Turbidity Meter with ClearSensor Technology 18 the sensor must be calibrated with suspended sediments from the waters to be monitored There is no standard turbidimeter design or universal formula for converting TU values to physical units such as mg l or ppm TU values have no intrinsic physical chemical or biological significance However empirical correlations between turbidity and environmental conditions established through field calibration can be useful in water quality investigations The USGS has an excellent chapter on turbidity measurements in their National Field Manual for the Collection of Water Quality Data http water usgs gov owg FieldManual Chapter6 Section6 7_v2 1 pdf Historically most turbidity sensor manufacturers and sensor users labelled the units NTUs for Nephelometric Turbidity Units ASTM and the USGS have come up with the following unit classifications that are applicable to the OBS501 Optical Backscatter FBU Formazin Backscatter Unit Sidescatter FNU Formazin Nephelometric Unit Ratio Back and Sidescatter FNRU Formazin Nephelometric Ratio Unit The document U S Geological Survey Implements New Turbidity Data Reporting Procedures details the units http water usgs gov owg turbidity TurbidityIn
17. wiper once every four hours This reduces the wear on the motor significantly and saves power The interval can be adjusted over time Increase the interval if experiencing fouling If the windows are staying clean slow it down even more Example CRBasic programs are provided at Appendix B 5 Examples for High Sediment Loads p B 5 a aM3 opens the wiper b aM4 aM5 or aM6 perform measurements when the wiper is open c aM7 closes the wiper User Manual Clean the shutter assembly The frequency that the shutter should be cleaned depends on the sediment load and can vary from weeks to months step 3 can help you determine the required frequency for cleaning Two levels of cleaning should be done a flush the wiper as it opens and closes with a stream of clean water or b remove the wiper from the OBS501 by removing one screw and follow the directions provided in Section 8 7 1 Wiper Removal Procedure p 29 Flush and clean Store the current used to open and close the slider The open and close SDI 12 instructions M3 and M7 output the current Normally the current is around 100 mA As sand grits lodge in the groves the resistance to movement increases and the motor has to work harder This increases the current usage Therefore increased current usage indicates that the wiper needs to be cleaned see step 2 Mount the sensor between 45 degrees pointing down to vertical hanging down 8 7 1 Wiper Removal Procedure
18. 1 0 Measure without moving the wiper Open 1 EndIf Call Output Tables CallTable Test NextScan EndProg B 6 Appendix C OBS501 Copper Sleeve Kit Installation 1 Remove the Button Head Hex Screw as shown 2 Slide the Copper Sleeve over the OBS501 and snap it into place C 1 Appendix D SDI 12 Sensor Support D 1 SDI 12 Command Basics SDI 12 commands have three components Sensor address a a single character and is the first character of the command The default address of zero 0 can be used unless multiple sensors are connected to the same port Command body M1 an upper case letter the command followed by alphanumeric qualifiers Command termination an exclamation mark An active sensor responds to each command Responses have several standard forms and terminate with lt CR gt lt LF gt carriage return line feed Standard SDI 12 commands supported by the OBS501 are listed in Table D 1 Table D 1 OBS501 SDI 12 Command and Response Set Name Command Response Menno WINGES al a lt CR gt lt LF gt Active Send al alleccccccemmmmmmvvvxxx xx lt CR gt lt LF gt Identification Change A Address aAb b lt CR gt lt LF gt AGGIES 2 a lt CR gt lt LF gt Query par aM atttnn lt CR gt lt LF gt Measurement Send Data aDv a lt values gt lt CR gt lt LF gt Start I Verification avi arin D 1 1 Address Query Command
19. 5 10 1 D 1 Factory Set vc toniolo lola dieta nilo 7 RS 232 Terminal CommandS i 9 SDI 12 Wiring RS 232 Wiring Analogue 0 5 Volt Wiring crac nnnncnnncanccn nos 13 OBSSOOCBL L Connector Pin Out i 19 SDI 12 and RS 232 Measurement Commands eeeereeee 20 RS 232 Setting cian 22 Calibration Materials and Volumes 23 Change in TU value resulting from one hour of evaporation of SDVB standard torrido 24 Troubleshooting Chart alare 32 OBS501 SDI 12 Command and Response Set D 1 OBS501 Smart Turbidity Meter with ClearSensor Technology 1 Introduction The OBS501 is a submersible turbidity meter that includes dual backscatter and sidescatter sensors shutter mechanism that keeps the lenses clean and a refillable biocide chamber that prevent fouling It s designed to prevent sand grains or packed sediment from getting wedged between the shutter and the sensor body which inhibits the shutter s movement The OBS501 has three communication modes SDI 12 RS 232 or 0 to 5 V The mode defaults to SDI 12 RS 232 but can be set in our Device Configuration Utility DevConfig to analogue As an SDI 12 RS 232 sensor the OBS501 is shipped with an address of 0 2 Cautionary Statements READ AND UNDERSTAND the Precautions section at the front of this manual The OBSS01 needs to be sent in after two years or 70 000 cycles f
20. 5 Volt Wiring eee eee ceseceecesecnseenseenee 13 T4 Programming aaa ERE ALe 13 TAA Using Short Cutie ied 13 7 4 2 CRBasic Programming eeeeeeeeeeeeeeeeeceseeesecssecaeenaeeaes 13 142 1 SDE Licuado 14 14 22 IA OO 14 TADS 4 Analogue rire aan 14 7 43 Edlog Programming ascii i 14 7 5 Mounting SuggestionS ii 15 Tvl Mounting Example iia 15 8 Operators LI 8 1 Turbidity Ulsa Ei 17 8 2 Vertical Cavity Surface Emitting Laser Diode 18 8 3 OBSS00CBL L Connector Pin Out esse ceeecneecneeeneeenes 19 8 4 Y E CUA e 19 8 5 Communication Modes ie 20 8 1 SDE1I2 a ipa ba nie aci 20 8 5 1 1 Measuring Multiple SDI 12 Sensors 22 8 5 2 RS 2 eau Li gale EEE AT EE 22 8 6 Calibrations E r ri 22 8 6 1 Turbidity io Alana ilaria 22 ISS 0 ececccccecececececececececececececeeseeeseeeseeeseeeeeeceeseeeess 26 8 6 2 1 Dry Sediment Calibration 00 0 0 ee eeeeeeceeeeeteeneees 26 8 6 2 2 Wet Sediment Calibration eee eeeeeeeeeeeeeeeees 26 8 6 2 3 In situ Calibration ii 27 8 6 2 4 Performing a Dry Sediment Calibration 27 8 7 Operation in High Sediment Loads and Sandy Sediments 28 8 7 1 Wiper Removal Procedure eeeeeeeeeeeeeeeeeeeseenseensees 29 9 Maintenance iio BI 10 TroubleshOoting s criari E
21. 5 instruction matches the control port number where the OBS501 is connected In the LoggerNet Connect screen navigate to the Datalogger menu and select Terminal Emulator The terminal emulator window will open In the Select Device menu located in the lower left hand side of the window select the CR10X station Click the Open Terminal button Press the lt enter gt key until the datalogger responds with the prompt To activate the SDI 12 Transparent Mode on control port p enter pX lt enter gt For this example key in 1X lt enter gt The datalogger will respond with entering SDI 12 If any invalid SDI 12 command is issued the datalogger will exit the SDI 12 Transparent Mode To query the OBS501 for its current SDI 12 address enter the command The OBS501 will respond with the current SDI 12 address To change the SDI 12 address enter the command aAb where a is the current address from the above step and b is the new address The OBS501 will change its address and the datalogger will exit the SDI 12 Transparent Mode Activate the SDI 12 Transparent Mode on Control Port 1 again by entering 1X lt enter gt Verify the new SDI 12 address by entering the command The OBS501 will respond with the new address 10 To exit the SDI 12 Transparent Mode enter Appendix D SDI 12 Sensor Support Terminal Emulator Edit Terminal Open 1X entering SDI 12 210 onl exiting SDI 12 1X All Caps Mode C Pause Clo
22. 501 to AMCO Clear turbidity The inset shows the response function of a turbidity sensor to high sediment concentrations AMCO Clear SDVB turbidity standards are used to calibrate an OBS501 sensor SDVB standards are made for individual instruments Standards made for one model of turbidity meter cannot be used to calibrate a different model Table 8 4 Calibration Materials and Volumes Calibration Cup Diameter Sidescatter 90 Degree Materials mm inches 8594 20 TU 100 4 8595 40 TU 100 4 8596 125 TU 100 4 8597 250 TU 100 4 8598 500 TU 100 4 8599 1000 TU 100 4 OBS Sensor Material 8600 125 TU 200 7 9 8601 250 TU 200 7 9 8602 500 TU 200 7 9 8603 1000 TU 100 4 8604 2000 TU 100 4 8605 4000 TU 100 4 The GFS item numbers standard values and volumes required for the standard low ranges are given in Table 8 4 SDVB standards have a shelf life of two years 23 OBS501 Smart Turbidity Meter with ClearSensor Technology provided that they are stored in tightly sealed containers and evaporation is minimized The TU values of the standards will remain the same as long as the ratio of particle mass number of particles to water mass volume does not change Evaporation causes this ratio to increase and dust bacteria growth and dirty glassware can also cause it to increase Therefore take the fo
23. CR23X CR23X PB CR23X TD CR3000 CR5000 CR510 CR510 PB CR510 TD CR800 Series CR9000X cs120 CS450 CS650 Series CWB100 CWS220 CWS655 CWS900 EC100 MD485 NL 100 PS200 CH200 RF400 RF401 RF430 RF450 RF500M 0B5500 OS Download Instructions Using this panel you can download a new operating system into an OBS500 sensor In order to download an operating system to the probe power 12 Volts DC must be available for the sensor You must also have a serial link to the sensor This is most easily done by using the OBS500 test cable When the sensor is connected as described above turn off the power to the sensor click on the Start button below A dialogue box will appear that will allow you to select the file that is to be sent as an operating system After you have selected a file and pressed OK in that dialogue restore power to the probe Once the initial synchronization takes place between this program and the sensor the operating system will be sent to the OBS500 Sent 417 of 1786 fragments Disconnect Figure 7 4 DevConfig Send OS 7 3 Datalogger RTU Connection The OBS500CBL L Field Cable connects the OBS501 to a datalogger or RTU see Section 8 3 OBSSOOCBL L Connector Pin Out p 19 Table 7 3 SDI 12 Wiring p 12 Table 7 4 RS 232 Wiring p 12 and Table 7 5 Analogue 0 5 Volt Wiring 13 provide wiring for connecting the OBSSOOCBL L Field Cable to a Campbell Scientific
24. Command requests the address of the connected sensor The sensor replies to the query with the address a D 1 2 Change Address Command aAb Sensor address is changed with command aAb where a is the current address and b is the new address For example to change an address from 0 to 2 the command is 0A2 The sensor responds with the new address b which in this case is 2 D 1 Appendix D SDI 12 Sensor Support D 1 3 Start Measurement Commands aM A measurement is initiated with M commands The response to each command has the form atttnn where a sensor address ttt time in seconds until measurement data are available nn the number of values to be returned when one or more subsequent D commands are issued D 1 4 Aborting a Measurement Command A measurement command M is aborted when any other valid command is sent to the sensor D 1 5 Send Data Command aDv This command requests data from the sensor It is normally issued automatically by the datalogger after measurement commands aMv In transparent mode the user asserts this command to obtain data D 2 SDI 12 Transparent Mode D 2 System operators can manually interrogate and enter settings in probes using transparent mode Transparent mode is useful in troubleshooting SDI 12 systems because it allows direct communication with probes Datalogger security may need to be unlocked before transparent mode can be activated Transparent mode is e
25. IVANVIA JASA rr f CAMPBELL LT SCIENTIFIC WHEN MEASUREMENTS MATTER OBS501 Smart Turbidity Meter with ClearSensor Technology Issued 21 7 15 Copyright O 2008 2015 Campbell Scientific Inc Printed under licence by Campbell Scientific Ltd CSL 1085 Guarantee This equipment is guaranteed against defects in materials and workmanship This guarantee applies for 24 months from date of delivery We will repair or replace products which prove to be defective during the guarantee period provided they are returned to us prepaid The guarantee will not apply to e Equipment which has been modified or altered in any way without the written permission of Campbell Scientific e Batteries e Any product which has been subjected to misuse neglect acts of God or damage in transit Campbell Scientific will return guaranteed equipment by surface carrier prepaid Campbell Scientific will not reimburse the claimant for costs incurred in removing and or reinstalling equipment This guarantee and the Company s obligation thereunder is in lieu of all other guarantees expressed or implied including those of suitability and fitness for a particular purpose Campbell Scientific is not liable for consequential damage Please inform us before returning equipment and obtain a Repair Reference Number whether the repair is under guarantee or not Please state the faults as clearly as possible and if the product is out of the guarantee perio
26. O2 Appendices A Importing Short Cut Code A 1 A l Importing Short Cut Code into a Program Editor A 1 ALLL GRBasie Datalogp t ia tn A 1 AD Elo ada A 2 B Example Programs 0000 Bo B 1 CR6SDI 12Program eee B 1 B 2 CR1000 SDI 12 Program ie B 2 B 3 CR1000 RS 232 Program e B 3 B 4 CR1000 Analogue Program iii B 4 B 5 Examples for High Sediment Loads eee ceeeeeeeeeeeeeeeeees B 5 B 5 1 Normally Open CR1000 Example nn B 5 B 5 2 Cycle Shutter Wiper for Each Measurement CR1000 ProgramB 6 C OBS501 Copper Sleeve Kit Installation C 1 D SDI 12 Sensor Support D 1 D 1 SDI 12 Command BasicS iii D 1 D 1 1 Address Query Command i D 1 D 1 2 Change Address Command 4AD D 1 D 1 3 Start Measurement Commands aM n D 2 D 1 4 Aborting a Measurement Command ii D 2 D 1 5 Send Data Command aDV i D 2 D 2 SDI 12 Transparent Mode ie D 2 D 2 1 CR200 X Series Datalogger Example D 2 D 2 2 CR1000 Datalogger Example i D 3 D 2 3 CRIOX Datalogger Example e D 4 E Factors that Affect Turbidity and Suspended Sediment Mea
27. be destroyed It is recommended that the cycles and moisture alarm be recorded regularly If a moisture alarm is recorded the sensor shutter should be parked and the sensor taken out of the water and returned for repair as soon as possible Other than the sleeve and the biocide chamber on the sensor tip there are no user serviceable parts inside the sensor housing Do not remove the sensor or connector from the pressure housing This will void the warranty and could cause a leak Plastic pn 27473 and copper pn 27803 sleeves are available for the OBS501 to reduce required cleaning The plastic sleeve is intended to be disposable The copper sleeve should slow fouling growth but it may need to be cleaned If the sleeve becomes encrusted with organisms such as barnacles or tube worms remove the sleeve The sleeve can be soaked in weak acids or other cleaning products that are compatible with copper The sleeve may have to be gently scraped with a flexible knife blade followed by a scouring pad such as SkotchBrite Do not use solvents such as MEK Toluene Acetone or trichloroethylene on OBS sensors 10 Troubleshooting A common cause for erroneous turbidity sensor data is poor sensor connections to the datalogger Problem Unit will not respond when attempting serial communications Suggestion Check the power Red is V and Black is Ground and signal White is SDI 12 Data lines to ensure proper connection to the datal
28. chnology 4 3 1 Ships With 1 Calibration Certificate 1 27752 OBS501 Spare Parts Kit 1 ResourceDVD Quickstart policy The contents of the package should also be inspected and a claim filed if any shipping related damage is discovered When opening the package care should be taken not to damage or cut the cable jacket If there is any question about damage having been caused to the cable jacket a thorough inspection is prudent The model number is engraved on the housing Check this information against the shipping documentation to ensure that the expected model number was received Refer to the Ships With list to ensure that all parts are included see Section 3 1 Ships With p 2 Short Cut is an easy way to program your datalogger to measure the sensor and assign datalogger wiring terminals The following procedure shows using Short Cut to program the OBS501 1 Install Short Cut by clicking on the install file icon Get the install file from either www campbellsci com the ResourceDVD or find it in installations of LoggerNet PC200W PC400 or RTDAO software ES SOUNE The Short Cut installation should place a Short Cut icon on the desktop of your computer To open Short Cut click on this icon User Manual 3 When Short Cut opens select New Program File Program Tools Help Test Progress Welcome to Short Cut Short Cut will 1 New Open help you generate a datalogger E program The basic step
29. d SCWin untitled scw Scan Interval 5 0000 Seco Elle Program Tools Help Progress CR1000 1 New Open CR1000 Wiring Diagram for untitied scw Wiring details can be found in the help file 2 Datalogger 3 Sensors 085500 Turb_BS Turb_SS Temp_C WD_OBS cue sod 12v 4 Outputs E White o 5 Finish Black e Clear Ground Wiring Diagram lt Wiring Text 7 Select any other sensors you have then finish the remaining Short Cut steps to complete the program The remaining steps are outlined in Short Cut Help which is accessed by clicking on Help Contents Programming Steps 8 If LoggerNet PC400 or PC200W is running on your PC and the PC to datalogger connection is active click Finish in Short Cut and you will be prompted to send the program just created to the datalogger User Manual 9 Ifthe sensor is connected to the datalogger as shown in the wiring diagram in step 6 check the output of the sensor in the datalogger support software data display to make sure it is making reasonable measurements 5 Overview 5 1 Applications Turbidity sensors are used for a wide variety of monitoring tasks in riverine oceanic laboratory and industrial settings They can be integrated in water quality monitoring systems CTDs laboratory instrumentation and sediment transport monitors The electronics of the OBS501 are housed in a Delrin package which is ideal for salt water or other harsh en
30. d it should be accompanied by a purchase order Quotations for repairs can be given on request It is the policy of Campbell Scientific to protect the health of its employees and provide a safe working environment in support of this policy a Declaration of Hazardous Material and Decontamination form will be issued for completion When returning equipment the Repair Reference Number must be clearly marked on the outside of the package Complete the Declaration of Hazardous Material and Decontamination form and ensure a completed copy is returned with your goods Please note your Repair may not be processed if you do not include a copy of this form and Campbell Scientific Ltd reserves the right to return goods at the customers expense Note that goods sent air freight are subject to Customs clearance fees which Campbell Scientific will charge to customers In many cases these charges are greater than the cost of the repair x CAMPBELL SCIENTIFIC Campbell Scientific Ltd 80 Hathern Road Shepshed Loughborough LE12 9GX UK Tel 44 0 1509 601141 Fax 44 0 1509 601091 Email support campbellsci co uk www campbellsci co uk PLEASE READ FIRST About this manual Mass Please note that this manual was originally produced by Campbell Scientific Inc primarily for the North American market Some spellings weights and measures may reflect this origin Some useful conversion factors Area 1 in square inch
31. datalogger Wiring to dataloggers or RTUs manufactured by other companies is similar NOTE Campbell Scientific recommends powering down the system before wiring the OBS501 The shield wire plays an important role in noise emissions and susceptibility as well as transient protection 11 OBS501 Smart Turbidity Meter with ClearSensor Technology 7 3 1 SDI 12 Wiring Table 7 3 SDI 12 Wiring CR800 CR500 CR5000 CR510 OBS501 CR3000 CR200X CR23X Colour Function CR1000 Series CR10X CR6 Red 12Vdc 12V Battery 12V 12V Power Black Ground G G G G Control White SDI 12 Control C1 Control Port or Signal Port SDI 12 Port Universal Channel Brown not used not used not used not used not used Blue not used not used not used not used not used Green not used not used not used not used not used Clear Shield G G G G Only odd control ports or universal channels can be used for SDI 12 for example C1 C3 7 3 2 RS 232 Wiring Our CR800 CR850 CR1000 and CR3000 dataloggers have COM ports control port Tx Rx pairs that can be used to measure RS 232 sensors Table 7 4 RS 232 Wiring RS 232 9 pin Colour DESSO Connection Datalogger Control Port Function Red 12VDC Power Source Black Power Ground Power Ground RS 232 Tx Pin 2 Rx Input Whe Output TARDI Control Port Rx RS 232 Rx Pin 3 Tx Output Blue Input Recente Control Port Tx Brown Green Clea
32. dity and temperature The OBS501 can also output a ratiometric measurement that combines the backscatter and sidescatter measurements Other diagnostic information is available see Table 8 2 SDI 12 and RS 232 Measurement Commands p 20 including the raw voltage output from the backscatter and the sidescatter sensors the current to open and close the shutter an open and close position count total open and close cycles and a moisture alarm The OBS501 is shipped from the factory to output turbidity in TU and temperature in degrees Celsius The analogue output supports backscatter and or sidescatter according to the status of a control line 19 OBS501 Smart Turbidity Meter with ClearSensor Technology 20 8 5 Communication Modes 8 5 1 SDI 12 The OBS501 uses an SDI 12 compatible hardware interface and supports a subset of the SDI 12 commands The most commonly used command is the aM command issued by the datalogger Here a represents the sensor address 0 to 9 The communication sequence begins with the datalogger waking the sensor and issuing the aM command The sensor responds to the datalogger indicating that two measurements will be ready within two 2 seconds Subsequent communications handle data reporting from the sensor to the datalogger The SDI 12 protocol has the ability to support various measurement commands The OBS501 supports the commands that are listed in Table 8 2 Table 8 2 SDI 12 and RS 232 Measurement C
33. e 8 3 OBS500CBL L Connector Pin Out The OBS500CBL L Field Cable terminates with an MCIL wet pluggable underwater terminator Table 8 1 shows the contact numbers for the MCIL MCBH 8 connectors and the electrical functions and wire colours Table 8 1 OBS500CBL L Connector Pin Out MCIL 8 MP MCBH 8 FS Contact Number Electrical Function Wire Colour Power Ground SDI 12 RS 232 TX Analogue Power 9 6 to 15 V Red Green RS 232 RX Shutter Open Brown Clear Braid Z Analogue Ground Z No Connection 8 4 Measurements The OBS501 design combines the sensor analogue measurement and signal processing within a single housing resulting in the integration of state of the art sensor and measurement technology The 24 bit A D has simultaneous 50 60 Hz rejection and automatic calibration for each measurement A number of additional advanced measurement techniques are employed to harness the best possible performance available from today s state of the art sensor technology The sensor reverts to a low power sleep state between measurements A series of measurements is performed yielding two turbidity and one temperature value This measurement cycle takes about 20 seconds The measurement cycle is activated by commands via SDI 12 RS 232 terminal commands or a control line s going high analogue measurements With SDI 12 and RS 232 the basic values output by the OBS501 are backscatter turbidity sidescatter turbi
34. e Low temperature coefficient Sidescatter sensors have the following advantages e More accurate in very clean water e Fixed measurement volume 5 3 ClearSensor Antifouling Method The OBS501 incorporates the ClearSensor U S Patent 8429952 anti fouling method to prevent biofouling which ensures better measurements in biologically active waters This method uses a shutter wiper mechanism to protect and clean the optics see Figure 5 1 Additionally biocide stored in a refillable chamber continuously leaches over the optics while the shutter is in the closed position OBS501 Smart Turbidity Meter with ClearSensor Technology Figure 5 1 OBS501 sensor with the shutter open 5 4 Comparison of 0BS500 and OBS501 The OBS501 provides the same functionality as the OBS500 but performs better in heavy sediment load environments This was accomplished by using a shutter and body design that eliminates parallel surfaces between moving parts wherever possible which prevents sand grains or packed sediment from getting wedged between the shutter and the sensor body The OBS501 also uses a flushing action that moves the sediment down and out of the cavity behind the shutter The OBS501 can sense if the shutter s motor is working harder than normal If it is the shutter moves slightly back and forth to dislodge sand grains before fully opening or closing Users who are particularly concerned about the sediment load can use SDI 12 instr
35. ecting the Settings Editor tab Device Configuration Utility 2 00 File Options Device Type AVW200 Series CCSMPX CC640 CD295 COM220 320 CRI CR10X PB CR 10X TD CR200 Series CR2 CR510 CR510 PB CR510 TD CR800 Series CR9000X CS120 CS450 CS650 Series CWS EC100 MD485 NL 100 PS200 CH200 Settings Editor Address o E OS Version 0 1200 m Send OS Terminal Current Setting OBS500 measurement v OBS500 Std 00 11 0xf764 OBS500 measurement mode Side scatter ratio top RF400 RF4OL poli 0BS500 measurement mode 2F450 oo Specifies measurement 0 SDI12 or RS232 1 Analog PC Serial Port COMI Baud Rate 9600 Apply Cancel FactoryDefaults Readrile Summary Figure 7 3 Settings Editor screen There are three settings that can be changed SDI 12 address measurement mode and sidescatter ratio top Select the desired values and press the Apply button NOTE The SDI 12 address is not used while in analogue mode 7 2 3 Downloading a New Operating System 10 DevConfig is used to download a new operating system to the OBS501 Select the Send OS tab and follow the directions on the screen User Manual Device Conf Uy 200 E File Options Help Device Type Send OS AVW200 Series CC5MPX CC640 CD295 COM220 COM320 CR 1000 CR 10X CR 10X PB CR 10X TD CR200 Series
36. ediment concentration is calculated in a spread sheet or database after the data is retrieved to a computer 8 6 2 1 Dry Sediment Calibration Dry sediment calibration is a calibration performed with sediment that has been dried crushed and turned to powder This is the easiest calibration to do because the amount of sediment can be determined accurately with an electronic balance and the volume of water in which it is suspended can be accurately measured with volumetric glassware Of the three methods dry sediment calibration causes the greatest physical and chemical alteration of the sediment Alteration of the sediment size as a result of processing can significantly affect the calibration slope Figure 8 2 Normalized response of OBSS01 to AMCO Clear turbidity p 23 shows for example that reducing the grain size by a factor of two during grinding can increase OBS sensitivity by a factor of two 8 6 2 2 Wet Sediment Calibration Wet sediment calibration is performed with sediment obtained from water samples or from the bed of a river that has not been dried and pulverized Consolidation and biochemical changes during storage and processing cause some alteration of wet sediment and for this reason sediment and water samples should be stored at about 4 C prior to use The wet sediment is introduced into the sediment suspender as it comes from the field This kind of calibration requires that water samples be withdrawn from the suspend
37. eezing ice may destroy the sensor 0 to 45 C 850 nm 9 6 to 18 Vdc lt 200 pA lt 40 mA lt 120 mA 200 mA for 50 ms when shutter motor starts Open measure close lt 25 s lt 2s SDI 12 version 1 3 1200 bps RS 232 9600 bps 8 data bits 1 stop bit no parity no flow control Analogue 0 to 5 V 100 m 328 ft 4 76 cm 1 875 in 27 cm 10 625 in 0 52 kg 1 15 lb 460 m 1500 ft 1 channel SDI 12 or Analogue 15 m 50 ft RS 232 If you are programming your datalogger with Short Cut skip Section 7 3 Datalogger RTU Connection 11 and Section 7 4 Programming p 13 Short Cut does this work for you See Section 4 Quickstart p 2 for a Short Cut tutorial Default Settings The OBS501 is configured at the factory with the default settings shown in Table 7 1 For most applications the default settings are used Table 7 1 Factory Settings SDI 12 Analogue SDI 12 RS 232 Baud Rate Temperature Units OBS501 Smart Turbidity Meter with ClearSensor Technology 7 2 Device Configuration Utility Device Configuration Utility DevConfig is used to change settings set up the analogue sensor enter RS 232 commands and update the operating system Use the OBS501 test cable to connect the OBS501 to a computer running DevConfig The red wire is connected to a 12 Vdc power supply and the black to ground The datalogger power supply is a good choice to use for the power supply DevConfig software
38. ement of slider is about 20 000 counts If it jams this will be smaller Alias obsDatOpen 2 Open Max _mA_cnts Number of times the shutter stops while opening because of max current Alias obsDatOpen 3 Open slip Open timeout count If the threads are stripped the slide will not move and this count will increase Alias obsDatOpen 4 Open_mA mA current of the motor Alias obsDatClose 1 Close counts Full movement of slider is about 20 000 counts If it jams this will be smaller Alias obsDatClose 2 Close Max_mA_cnts Number of times the shutter stops while opening because of max current Alias obsDatClose 3 Close slip Open timeout count If the threads are stripped the slide will not move and this count will increase Alias obsDatClose 4 Close mA mA current of the motor Units turb_bs fbu Units turb_ss fnu Units tempC_0BS501 degC Units wet_dry YesNo Define Data Tables DataTable Test 1 1000 DataInterval 0 5 Min 10 Sample 1 turb_bs FP2 Sample 1 turb_ss FP2 EndTable Main Program BeginProg Scan 60 Sec If open make measurement and close If closed open then make measurement If Open 1 Then If open the make measurement then close SDI12Recorder 0BS501 1 0 M4 1 0 Measure without moving the wiper SDI12Recorder obsDatClose 1 0 M7 1 0 Close wiper Open 0 Else if closed SDI12Recorder obsDatOpen 1 0 M3 1 0 Open wiper Delay 0 11 Sec SDI12Recorder 0BS501 1 0 M4
39. er after each addition of sediment for the determination of SSC suspended sediment concentration by filtration and gravimetric analysis User Manual 8 6 2 3 In situ Calibration In situ calibration is performed with water samples taken from the immediate vicinity of an OBS sensor in the field over sufficient time to sample the full range of SSC values to which a sensor will be exposed SSC values obtained for these samples with concurrent recorded OBS501 signals and regression analysis establishes the mathematical relation for future SSC conversions by an instrument This is the best sediment calibration method because the particles are not altered from their natural form in the river see Lewis 1996 It is also the most tedious expensive and time consuming method It can take several years of water sampling with concurrent OBS measurements to record the full range of SSC values on a large river 8 6 2 4 Performing a Dry Sediment Calibration Materials and equipment OBS501 with test cable dry disaggregated sediment from the location where the OBS501 will be used sediment should be in a state where grinding sieving or pulverization does not change its particle size distribution datalogger with 12 V power supply sediment suspender if a suspender is not available use a 200 mm I D dark plastic container and a drill motor with paint mixing propeller electronic balance calibrated with 10 mg accuracy 20 ml weigh boats large black
40. erials and tools Utility and Electrical e You can be killed or sustain serious bodily injury if the tripod tower or attachments you are installing constructing using or maintaining or a tool stake or anchor come in contact with overhead or underground utility lines e Maintain a distance of at least one and one half times structure height or 20 feet or the distance required by applicable law whichever is greater between overhead utility lines and the structure tripod tower attachments or tools e Prior to performing site or installation work inform all utility companies and have all underground utilities marked e Comply with all electrical codes Electrical equipment and related grounding devices should be installed by a licensed and qualified electrician Elevated Work and Weather e Exercise extreme caution when performing elevated work e Use appropriate equipment and safety practices e During installation and maintenance keep tower and tripod sites clear of un trained or non essential personnel Take precautions to prevent elevated tools and objects from dropping e Do not perform any work in inclement weather including wind rain snow lightning etc Maintenance e Periodically at least yearly check for wear and damage including corrosion stress cracks frayed cables loose cable clamps cable tightness etc and take necessary corrective actions e Periodically at least yearly check electrical ground connecti
41. ff event Load Estimation Water Resources Research 32 7 pp 2299 2310 U S Geological Survey Implements New Turbidity Data Reporting Procedures U S Geological Survey http water usgs gov owq turbidity TurbidityInfoSheet pdf 32 Appendix A Importing Short Cut Code This tutorial shows e How to import a Short Cut program into a program editor for additional refinement e How to import a wiring diagram from Short Cut into the comments of a custom program A 1 Importing Short Cut Code into a Program Editor Short Cut creates files that can be imported into either CRBasic Editor or Edlog program editor These files normally reside in the C campbellsci SCWin folder and have the following extensions DEF wiring and memory usage information CR6 CR6 datalogger code CR2 CR200 X datalogger code CR1 CR1000 datalogger code CR8 CR800 datalogger code CR3 CR3000 datalogger code CR5 CR5000 datalogger code DLD contain code for CR10 X CR23X CR500 or CR510 dataloggers The following procedures show how to import these files for editing A 1 1 CRBasic Datalogger Use the following procedure to import Short Cut code into CRBasic Editor CR6 CR200 X CR1000 CR800 CR3000 CR5000 dataloggers NOTE 1 Create the Short Cut program following the procedure in Section 4 Quickstart p 2 Finish the program and exit Short Cut Make note of the file name used when saving the Short Cut program
42. foSheet pdf 8 2 Vertical Cavity Surface Emitting Laser Diode OBS501 sensors detect suspended matter in water and turbidity from the relative intensity of light backscattered at angles ranging from 125 to 170 and at 90 for the sidescatter measurement A 3D schematic of the main components of the sensor is shown in Figure 8 1 The OBSS01 light source is a Vertical Cavity Surface Emitting Laser diode VCSEL which converts 5 mA of electrical current to 2000 uW of optical power The detectors are low drift silicon photodiodes with enhanced NIR responsivity NIR responsivity is the ratio of electrical current produced per unit of light power in air or water A light baffle prevents direct illumination of the detector by the light source and in phase coupling that would otherwise produce large signal biases A daylight rejection filter blocks visible light in the solar spectrum and reduces ambient light interference In addition to the filter a synchronous detection circuit is used to eliminate the bias caused by ambient light The VCSEL is driven by a temperature compensated Voltage Controlled Current Source VCCS OBS Detector 7 Cone Emitter Cone 90 Side scatter Detector Cone Figure 8 1 Orientation of emitter cone source beam and OBS and sidescatter detector acceptance cones User Manual The beam divergence angle of the VCSEL source is 4 worst case and 2 typical 95 of the beam power is contained within a 5 con
43. g differs by more than 5 from ones reported on the factory calibration certificate or the user s own calibration data the sensor should be recalibrated If the first two calibration points fall within the acceptance criterion the third value can be tested The recommended frequency for calibration checks is quarterly when an OBS sensor is in regular use Otherwise it should be performed prior to use Calibration checks can be done in the field Table 10 1 Troubleshooting Chart Fails finger No power dead battery Replace battery and reconnect wave test wires Plug not fully seated Disconnect and reinsert plug Sensor broken Visually inspect for cracks return OBS501 to manufacturer if cracks are found Electronic failure Unit Return OBS501 to manufacturer draws less than 11 mA or more than 40 mA Fails shake Sensor leaked Return OBS501 to manufacturer test Fails Aging of light source causes Recalibrate see Section 8 6 calibration 1t to become dimmer with Calibration p 22 check time 11 References Anderson C W 2005 Turbidity ver 2 1 U S Geological Survey Techniques of Water Resources Investigations book 9 chap A6 sec 6 7 Sept 2005 accessed December 8 2011 from http pubs water usgs gov twri9A6 Boyd Bringhurst and Jeff Adams Innovative Sensor Design for Prevention of Bio fouling Oceans 2011 September 2011 Lewis Jack 1996 Turbidity controlled Suspended Sediment Sampling for Runo
44. ickstart p 2 Finish the program and exit Short Cut Make note of the file name used when saving the Short Cut program Open Edlog Click File Document DLD File Assuming the default paths were used when Short Cut was installed navigate to CACampbellScASCWin folder The file of interest has a DLD extension Select the file and click Open The dld file which is a type of ASCII machine code is imported documented and when saved given a CSI extension Immediately save the file in a folder different from Campbellsci SCWin or save the file with a different file name Once the file is edited with Edlog Short Cut can no longer be used to edit the program Change the name of the program file or move it or Short Cut may overwrite it The program can now be edited saved and sent to the datalogger Import wiring information to the program by opening the associated DEF file Copy and paste the section beginning with heading Wiring for CRXXX into the Edlog program usually at the head of the file After pasting edit the information such that a semicolon begins each line which instructs the datalogger compiler to ignore the line when compiling the datalogger code Appendix B Example Programs B 1 CR6 SDI 12 Program CR6 Series Declare Variables and Units Public BattV Public PTemp_C Public 0BS501 4 Alias 0BS501 1 Turb_BS Alias 0BS501 2 Turb_SS Alias 0BS501 3 Temp_C Alias 0BS501 4
45. ing the unit with the frame or the wire 7 5 1 Mounting Example Figure 7 5 Use strain relief to keep stress off the cable and provide extra security 15 OBS501 Smart Turbidity Meter with ClearSensor Technology Dual Path 501 Turbidity Meter La SA ELL Made in USA AMRTIFIG SN 100000 Figure 7 6 Apply tape to protect sensor pual Path Smart A 501 Turbidity Meter eo ei PBELL 7 Figure 7 7 Secure with hose clamps do not overtighten 16 User Manual Figure 7 8 Place and secure mounting fixture 8 Operation 8 1 Turbidity Units Conceptually turbidity is a numerical expression in turbidity units TU of the optical properties that cause water to appear hazy or cloudy as a result of light scattering and absorption by suspended matter Operationally a TU value is interpolated from neighbouring light scattering measurements made on calibration standards such as Formazin StablCal or styrene divinylbenzene SDVB beads Turbidity is caused by suspended and dissolved matter such as sediment plankton bacteria viruses and organic and inorganic dyes In general as the concentration of suspended matter in water increases so will its turbidity as the concentration of dissolved light absorbing matter increases turbidity will decrease Descriptions of the factors that affect turbidity are given in Appendix E Factors that Affect Turbidity and Suspended Sediment Measurements p E 1 Like all
46. ithin the product or used during the products life should be removed from the product and also be sent to an appropriate recycling facility Campbell Scientific Ltd can advise on the recycling of the equipment and in some cases Ci arrange collection and the correct disposal of it although charges may apply for some items or territories For further advice or support please contact Campbell Scientific Ltd or your local agent CAMPBELL SCIENTIFIC Campbell Scientific Ltd 80 Hathern Road Shepshed Loughborough LE12 9GX UK Tel 44 0 1509 601141 Fax 44 0 1509 601091 Email support campbellsci co uk www campbellsci co uk Precautions DANGER MANY HAZARDS ARE ASSOCIATED WITH INSTALLING USING MAINTAINING AND WORKING ON OR AROUND TRIPODS TOWERS AND ANY ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS CROSSARMS ENCLOSURES ANTENNAS ETC FAILURE TO PROPERLY AND COMPLETELY ASSEMBLE INSTALL OPERATE USE AND MAINTAIN TRIPODS TOWERS AND ATTACHMENTS AND FAILURE TO HEED WARNINGS INCREASES THE RISK OF DEATH ACCIDENT SERIOUS INJURY PROPERTY DAMAGE AND PRODUCT FAILURE TAKE ALL REASONABLE PRECAUTIONS TO AVOID THESE HAZARDS CHECK WITH YOUR ORGANIZATION S SAFETY COORDINATOR OR POLICY FOR PROCEDURES AND REQUIRED PROTECTIVE EQUIPMENT PRIOR TO PERFORMING ANY WORK Use tripods towers and attachments to tripods and towers only for purposes for which they are designed Do not exceed design limits Be familiar and co
47. llowing precautions 1 Always use clean glassware and calibration containers 2 Don t leave standards on the bench in open containers or leave the standard bottles uncapped Perform the calibration as quickly as possible and return the AMCO solutions to their bottles 3 Clean dirty sensors with a clean alcohol soaked cloth to sterilize them before dipping them into the standards 4 Transfer entire bottles between containers To avoid aeration do not shake excess fluid off the glassware Because of the intrinsic errors in the TU value of formazin used by the SDVB manufacturer GFS Chemicals and the dilution procedures the uncertainty in the TU value of an SDVB standard is 1 of the value indicated on the standard bottle Consequently the TU value of one litre of standard in an uncovered 100 mm calibration cup will increase 1 in 10 hours on a typical summer day relative humidity 90 and air temperature 18 C For example the TU value of a 2000 TU standard in a 100 mm cup will increase by about 2 TU 0 1 per hour Table 8 5 gives the increases for some other commonly used standards Table 8 5 Change in TU value resulting from one hour of evaporation of SDVB standard Calibration cup Size mm in 250 TU 500 TU 2000 TU 4000 TU Materials and equipment used in the procedure OBS501 with cable datalogger large black polyethylene plastic tub 0 5 M I D X 0 25 M deep for measuring the clear water points and 100 mm a
48. most of the time bubble concentrations are at least two orders of magnitude less than sand concentrations This means that sand will produce much more backscatter than bubbles in most situations and bubble interference will not be significant Prop wash from ships and small clear mountain streams where aeration produces high bubble concentrations are exceptions to this generality and can produce erroneous turbidity values resulting from bubbles OBS sensors detect IR backscattered between 90 and 165 where the scattering intensities are nearly constant with the scattering angle Particle concentration has the most significant effect in this region OBS sensors are more sensitive by factors of four to six to mineral particles than particulate organic matter and interference from these materials can therefore be ignored most of the time One notable exception is where biological productivity is high and sediment production from rivers and re suspension is low In such an environment OBS signals can come predominately from plankton E 5 CAMPBELL SCIENTIFIC COMPANIES Campbell Scientific Inc CSI 815 West 1800 North Logan Utah 84321 UNITED STATES www campbellsci com e info campbellsci com Campbell Scientific Africa Pty Ltd CSAf PO Box 2450 Somerset West 7129 SOUTH AFRICA www csafrica co za e sales csafrica co za Campbell Scientific Australia Pty Ltd CSA PO Box 8108 Garbutt Post Shop QLD 4814 AUSTRALIA www ca
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50. mply with all instructions provided in product manuals Manuals are available at www campbellsci eu or by telephoning 44 0 1509 828 888 UK You are responsible for conformance with governing codes and regulations including safety regulations and the integrity and location of structures or land to which towers tripods and any attachments are attached Installation sites should be evaluated and approved by a qualified engineer If questions or concerns arise regarding installation use or maintenance of tripods towers attachments or electrical connections consult with a licensed and qualified engineer or electrician General e Prior to performing site or installation work obtain required approvals and permits Comply with all governing structure height regulations such as those of the FAA in the USA e Use only qualified personnel for installation use and maintenance of tripods and towers and any attachments to tripods and towers The use of licensed and qualified contractors is highly recommended e Read all applicable instructions carefully and understand procedures thoroughly before beginning work e Wear a hardhat and eye protection and take other appropriate safety precautions while working on or around tripods and towers e Do not climb tripods or towers at any time and prohibit climbing by other persons Take reasonable precautions to secure tripod and tower sites from trespassers e Use only manufacturer recommended parts mat
51. ncentrations ii 23 Position of OBSSOI in clean tap water in big black tub 25 OBS501 in 500 TU AMCO Clear turbidity standard in 100 mm black polyethylene calibration CUP ii 26 Portable Sediment Suspender left and OBS beam orientation in suspender tub right iii 27 Remove the SCE Wes onc lla allen alan 29 Insert screwdriver and rotate clockwise 30 Shutter disassembled cnn conc cnn ncnnccnnoo 30 Shutter components sisirain enrere si esens Ess 30 CR200 X example of using the SDI 12 transparent mode to change the SDI 12 address from 0 to 1 eee eeeeceeeee D 3 CR1000 example of using the SDI 12 transparent mode to change the SDI 12 address from 3 to 1 Sensor is connected to control port liana add D 4 CR10X example of using the SDI 12 transparent mode to change the SDI 12 address from 0 to 1 Sensor is connected to control port listan anida D 5 Normalized sensitivity as a function of grain diameter E 1 The apparent change in turbidity resulting from disaggregation methods steve tii E 2 Relative scattering intensities of grain shapes E 3 Response of an OBS sensor to a wide range of SSC E 4 Infrared reflectivity of minerals as a function of 10 Munzell A aa SA Annis eile E 5 Tables 7 1 7 2 7 3 7 4 7 5 8 1 8 2 8 3 8 4 8
52. nd 200 mm black PE polyethylene calibration cups Procedure 1 Swab sensor with an alcohol soaked towel to sterilize it Position the OBS sensor in a large black tub of fresh tap water as shown in Figure 8 3 and record a 10 s average of the low range output Record the average output on the calibration log sheet 24 User Manual Figure 8 3 Position of OBS501 in clean tap water in big black tub 2 Pour the first SDVB standard into the appropriately sized cup see Table 8 5 3 Position the OBS sensor in the cup as shown in Figure 8 4 and record 10 s averages of the low and high range outputs Record the average outputs on the calibration log sheet 4 Pour the standard back into its container 5 Wipe sensor with a clean dry towel to remove residual standard 6 Repeat steps 2 3 4 and 5 for the other standards 7 Perform 2 order polynomial regressions on the calibration data to get the coefficients for converting OBS signals to TU values 25 OBS501 Smart Turbidity Meter with ClearSensor Technology 26 8 6 2 Sediment Figure 8 4 OBS501 in 500 TU AMCO Clear turbidity standard in 100 mm black polyethylene calibration cup There are three basic ways to calibrate an OBS sensor with sediment These are described in the following sections However only the procedures for dry sediment are explained in this manual Typically the sensor will record in turbidity units and the relationship to suspended s
53. ns exceeding 6 000 mg l cause the output signal to decrease It is recommended not to exceed the specified turbidity or suspended sediment ranges otherwise the interpretation of the signal can be ambiguous For example a signal level of 2 000 mV Figure E 4 could be interpreted to indicate SSC values of either 3 000 or 33 000 mg l Factory calibrations are performed in the linear region designated A on the graph E 3 Appendix E Factors that Affect Turbidity and Suspended Sediment Measurements 4000 3000 2000 Signal mV 1000 0 20000 40000 60000 SSC mg l Figure E 4 Response of an OBS sensor to a wide range of SSC E 5 IR Reflectivity Sediment Colour E 4 Infrared reflectivity indicated by sediment colour has a major effect on sensitivity because with other factors remaining constant it changes the intensity of light scattering Although turbidity sensors are colour blind tests have shown that whiteness colour and IR reflectivity are correlated Calcite which is highly reflective and white in colour will produce a much stronger turbidity signal on a mass concentration basis than magnetite which is black and IR absorbing Sensitivity to coloured silt particles varies from a low of about one for dark sediment to a high of about ten for light grey sediment see Figure E 5 In areas where sediment colour is changing with time a single calibration curve may not work Resulting errors will depend
54. ntered while the PC is in telecommunications with the datalogger through a terminal emulator program It is easily accessed through Campbell Scientific datalogger support software but is also accessible with terminal emulator programs such as Windows HyperTerminal Datalogger keyboards and displays cannot be used The terminal emulator is accessed by navigating to the Datalogger menu in PC200W the Tools menu in PC400 or the Datalogger menu in the Connect screen of LoggerNet The following examples show how to use LoggerNet software to enter transparent mode and change the SDI 12 address of an OBS501 sensor The same steps are used to enter transparent mode with PC200W and PC400 software after accessing the terminal emulator as previously described D 2 1 CR200 X Series Datalogger Example 1 Connect a single OBS501 to the CR200 X see Table 7 3 2 In the LoggerNet Connect screen navigate to the Datalogger menu and select Terminal Emulator The terminal emulator window will open In the Select Device menu located in the lower left hand side of the window select the CR200Series station 3 Click on the Open Terminal button 4 Press the lt enter gt key until the datalogger responds with the CR2XX gt prompt At the CR2XX gt prompt make sure the All Caps Mode box is checked and enter the command SDI 2 lt enter gt The response SDI 2 gt indicates that the OBS501 is ready to accept SDI 12 commands Appendix D SDI 12 Sensor Suppor
55. ogger Check the datalogger program to ensure that the same port the SDI 12 data line is connected to is specified in the measurement instruction The following three tests are used to diagnose malfunctions of an OBS501 1 The Finger Wave Test is used to determine if an OBS sensor is alive Power the OBS sensor and connect datalogger see Section 7 2 Device Configuration Utility p 8 Wave your finger across the sensor window about 20 mm away from it The datalogger should show the output fluctuating from a few TU to the full scale signal If there are no signal fluctuations of this order there is a problem that requires attention 31 OBS501 Smart Turbidity Meter with ClearSensor Technology 2 The Shake Test is done to determine if water has leaked inside the pressure housing Unplug the cable and gently shake the sensor next to your ear and listen for sloshing water This test gives a false negative result when the amount of water in the housing is large enough to destroy the circuit but too small to be audible 3 A Calibration Check is done to verify if a working OBS sensor needs to be recalibrated In order to be meaningful the user must have a criterion for this test For example this criterion might be 5 The sensor is placed in calibration standards with the 1 and 2 TU values listed in Figure 8 2 Normalized response of OBS501 to AMCO Clear turbidity p 23 and the datalogger readings are logged If either readin
56. ogram Although this is a CR1000 program other CRBasic dataloggers are programmed similarly CR1000 Series Datalogger Declare Public Variables Public RS232 5 Public Counter Public OutString As String 20 Public OutString2 As String 10 Public InString As String 100 Declare Other Variables RS232 1 is the address Alias RS232 2 OBS Alias RS232 3 SS Alias RS232 4 Temp Alias RS232 5 WetDry Define Data Tables DataTable Test 1 1000 DataInterval 0 60 Min 10 Sample 1 0BS FP2 Sample 1 SS FP2 Sample 1 Temp FP2 Sample 1 WetDry FP2 EndTable Main Program BeginProg SerialOpen Com1 9600 0 0 150 Scan 30 Sec 0 0 OutString2 CHR 13 OutString OM CHR 13 a series of carriage returns will put 0BS501 into RS 232 mode address and then use commands M to M8 Send String over communication port C1 COM1 TX SerialOut Com1 OutString2 0BS_500 15 100 put OBS5 1 into RS232 mode delay 1 1 Sec SerialOut Com1 OutString 0 1000 send command Receive String over communication port C1 COM1 RX SerialIn InString Com1 5 33 150 SerialIn InString Com1 2500 62 150 SerialIn InString Com1 100 13 200 SplitStr RS232 InString 5 0 Call Output Tables Example CallTable Test NextScan EndProg The sensor echoes back the command ending with an CHR 33 The sensor will open close and after about 20 seconds send 0BS_500 gt and then the data
57. ommands aM aC a address Open Wiper Measure Close Send Data Open Wiper Measure Close Send Data Open Wiper Measure Close Send Data Open Wiper Send Data Measure Send Data obs TU ss TU temperature C wet dry 0 dry 1 wet burst data bs median bs mean bs standard deviation bs minimum bs maximum ss median ss mean ss standard deviation ss minimum ss maximum obs TU ss TU ratio TU temperature C raw obs V raw ss V open current mA close current mA wet dry 0 dry 1 wet open wiper position count open max current count open timeout count open current mA total open close count obs TU ss TU temperature C wet dry 0 dry 1 wet NOTE User Manual Table 8 2 SDI 12 and RS 232 Measurement Commands aM6 aC6 aM7 aC7 aC8 Measure Send Data Measure Send Data Close Wiper Send Data Measure Send Data Close Open Send Data burst data bs median bs mean bs standard deviation bs minimum bs maximum ss median ss mean ss standard deviation ss minimum ss maximum obs TU ss TU ratio TU temperature C raw obs V raw ss V open current mA close current mA wet dry 0 dry 1 wet close wiper position count close max current count close timeout count close current mA total open close count raw burst data V bs median bs mean bs standard deviation bs minimum bs
58. ons WHILE EVERY ATTEMPT IS MADE TO EMBODY THE HIGHEST DEGREE OF SAFETY IN ALL CAMPBELL SCIENTIFIC PRODUCTS THE CUSTOMER ASSUMES ALL RISK FROM ANY INJURY RESULTING FROM IMPROPER INSTALLATION USE OR MAINTENANCE OF TRIPODS TOWERS OR ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS CROSSARMS ENCLOSURES ANTENNAS ETC Contents PDF viewers These page numbers refer to the printed version of this document Use the PDF reader bookmarks tab for links to specific sections 1 introduction ili 2 Cautionary StatementS occccccccconononanannnncnnnnnnnonanananas 1 3 Initial INSPECTION rcerreree rene ni ene nina I 3 1 Ships Witt hire 2 4 Quickstartiiaiaa O nia O A A EE 5 1 Applications seitens isis derrotar ares anioni 5 5 2 Backscatter and Sidescatter Sensors i 5 5 3 ClearSensor Antifouling Method in 5 5 4 Comparison of OBS500 and OBSS01 eeeeeceeeeeeeeeseeesees 6 6 Specifications s sisien tinirua ii A Sl A taria 7 1 Default Setenil ptas 7 7 2 Device Configuration Utility iii 8 7 24 Terminal T b orrai cinese iodo ei o oA 8 7 2 2 Setting Editor Tabi enii seo i sis 10 7 2 3 Downloading a New Operating System ii 10 7 3 Datalogger RTU Connection corona nono nccnncnnos 11 TBA SDELZ Waning smilies iia dde 12 7 3 2 RS 232 Wires ricino dei dido ds 12 7 3 3 Analogue 0 to
59. or drive shaft seal replacement See aM9 command in Table 8 2 SD 2 and RS 232 Measurement Commands p 20 The sensor may be damaged if it is encased in ice Damages caused by freezing conditions will not be covered by our warranty Campbell Scientific recommends removing the sensor from the water for the time period that the water is likely to freeze Minimize temperature shock For example do not take sensor from sunny dashboard and immediately drop it in frigid water Ensure that obstructions are not in the backscatter sensor s large field of view See Section 7 5 Mounting Suggestions p 15 for more information Maximum depth for the OBS501 is 100 m The probe must be calibrated with sediments from the waters to be monitored The procedure for calibrating the probe is provided in Section 8 6 Calibration p 22 Sites with high sediment loads or large sand grains can be problematic for the shutter and it s motor Refer to Section 8 7 Operation in High Sediment Loads and Sandy Sediments p 28 for more information Remember that although the OBS501 is designed to be a rugged and reliable device for field use it is also a highly precise scientific instrument and should be handled as such 3 Initial Inspection Upon receipt of the OBS501 inspect the packaging for any signs of shipping damage and if found report the damage to the carrier in accordance with OBS501 Smart Turbidity Meter with ClearSensor Te
60. pen mode the 0BS501 can make measurement multiple times per minute but the wiper interval could be set to as low as a time or two a day This mode is also beneficial where the power budget is critical since opening and closing the wiper consumes considerably more power than making the turbidity measurement Declare Public Variables Public 0BS501 4 Public TimeCounter Public obsDatOpen 4 obsDatClose 4 Declare Other Variables ias 0BS501 1 turb_bs ias 0BS501 2 turb_ss ias 0BS501 3 tempC_0BS501 ias 0BS501 4 wet_dry ias obsDatOpen 1 Open _counts Full movement of slider is about 20 000 counts If it jams this will be smaller ias obsDatOpen 2 Open Max_mA_cnts Number of times the shutter stops while opening because of max current ias obsDatOpen 3 Open slip Open timeout count If the threads are stripped the slide will not move and this count will increase ias obsDatOpen 4 Open_mA mA current of the motor ias obsDatClose 1 Close counts Full movement of slider is about 20 000 counts If it jams this will be smaller ias obsDatClose 2 Close Max_mA_cnts Number of times the shutter stops while opening because of max current ias obsDatClose 3 Close slip Open timeout count If the threads are stripped the slide will not move and this count will increase ias obsDatClose 4 Close mA mA current of the motor 2RAaARERAAR ERA Units turb_bs fbu Units turb_ss fnu Units tempC_0BS501 degC
61. polyethylene plastic tub for measuring the clear water points 1 litre class A volumetric flask tea cup with round bottom and teaspoon 1 Check the balance with calibration weights recalibrate if necessary 2 Connect the OBS501 to a computer or a datalogger so that the measured values can be observed 3 Add three litres of tap water to the suspender tub with the volumetric flash 4 After measuring the clear water signal Step 1 Section 8 6 1 Turbidity p 22 mount the OBS501 so that the sensor end is 50 mm above the bottom of the suspender tub and secure it in the position that minimizes reflections from the wall see Figure 8 5 Figure 8 5 Portable Sediment Suspender left and OBS beam orientation in suspender tub right SSC Wts Vw Wtsy ps where Wts total sediment weight in tub in mg Vw volume of water in litres and ps sediment density assume 2 65 10 mg L 27 OBS501 Smart Turbidity Meter with ClearSensor Technology 28 8 7 Operation NOTE Procedure 1 Record and log the clean water signal as in Step 1 Section 8 6 1 Turbidity p 22 see Figure 8 3 Position of OBSSOI in clean tap water in big black tub p 25 Use the same value such as sidescatter backscatter or ratio throughout the calibration Move the OBS501 to the suspender as described in setup Weigh 500 10 mg of sediment in a weigh boat and transfer it to the teacup Record the weight on the calibration log sheet
62. r Shield GND Ground 12 User Manual 7 3 3 Analogue 0 to 5 Volt Wiring Table 7 5 Analogue 0 5 Volt Wiring CR6 CR800 CR850 CR1000 CR3000 CR5000 Colour Description CR23X CR10X Control Port or Shutter Open Control High Universal Channel White Backscatter Low or Control Port or Sidescatter High Control Universal Channel Gea Sienal Differential High or 5 Single Ended Input Differential Low or Ano gue Ground Analogue Ground Power Ground Red Power SW12V The measurement sequence is to raise the blue wire from ground to 5 volts to open the shutter delay 6 seconds and then measure the backscatter analogue output on the green wire If sidescatter is desired then raise the white wire from ground to 5 volts delay 3 seconds and then measure the sidescatter analogue output on the green wire In either case lower the blue wire to ground to close the shutter Note that measurements can be differential or single ended Differential measurements are recommended The output is scaled as 1 mV per TU For example 100 mV 100 TU 4000 mV 4000 TU 7 4 Programming 7 4 1 Using Short Cut NOTE Short Cut is the easiest and typically the preferred method for programming the datalogger Short Cut generates a wiring diagram that shows how to connect the OBS501 to your Campbell Scientific datalogger The sections that immediately follow are for CRBasic and Edlog programming Short Cut users can j
63. s are 1 Create New Open Program 2 Select Datalogger 3 Select Sensors 4 Select Outputs 5 Finish Compile the Program lt I Click New Program to begin Click Open Program to open an open Prog existing Short Cut program 4 Select Datalogger Model and Scan Interval default of 5 seconds is OK for most applications Click Next File Program Tools Help Test Progress Select the Datalogger Model for New Open which you wish to create a ogram Datalogger ud Sensors Outputs Scan Interval Select the Scan Interval Finish This is how frequently 5 Seconds rs measurements are made Wiring Wiring Diagram Wiring Text OBS501 Smart Turbidity Meter with ClearSensor Technology 5 Under the Available Sensors and Devices list select the Sensors Water Quality folder Select OBS501 Smart Turbidity Meter Click E to move the selection to the Selected device window Temperature defaults to degrees Celsius and the sensor are measured every scan These can be changed by clicking the Temperature or Measure Sensor box and selecting a different option Typically the default SDI 12 address of 0 is used ND Bert CA LO C ComptetizWineatind som Sen Interval 3 0000 O Avalable Sensors and Devices Selected D 1000 Serene Me t sason lt ia TT muta Ca Conan MEurements 2 T Geotectuucai amp Structural Detauit Batty DA Metocesiopca PTemp_c Gi Macelanecus Sensors Temperatura 20 Water
64. se Terminal Clear Select Device Baud Rate Figure D 3 CR10X example of using the SDI 12 transparent mode to change the SDI 12 address from 0 to 1 Sensor is connected to control port 1 D 5 Appendix D SDI 12 Sensor Support D 6 Appendix E Factors that Affect Turbidity and Suspended Sediment Measurements This appendix summarizes some of the factors that affect OBS measurements and shows how ignoring them can lead to erroneous data If you are certain that the characteristics of suspended matter will not change during your survey and that your OBS was factory calibrated with sediment from your survey site you only need to skim this section to confirm that no problems have been overlooked E 1 Particle Size The size of suspended sediment particles typically ranges from about 0 2 to 500 um in surface water streams estuaries and ocean With size shape and colour remaining constant particle area normal to a light beam will determine the intensity of light scattered by a volume of suspended matter Results of tests with sediment shown in Figure E 1 indicate a wide range of sensitivity is associated with fine mud and coarse sand about two orders of magnitude The significance of these results is that size variations between the field and he laboratory and within a survey area during monitoring will produce shifts in apparent TU and SSC values that are unrelated to real changes in sediment concentration OBS Sensi
65. surements 1 serre 1 Ed Particle Sizes iio Leali E 1 E 2 Suspensions with Mud and Sand eee cee ceee cree ceeeeeeeeeeeee E 2 E 3 Particle Shape Effects escarit sei ess E 2 E 4 High Sediment Concentrations i E 3 ES IR Reflectivity Sediment COlour i E 4 E Water Colob ssn io iii E 5 E 7 Bubbles and Plankton ee eeceeecesecesecesecseecaeecaeesaeeeeeeeeeees E 5 Figures 5 1 7 1 7 2 7 3 7 4 7 5 7 6 7 7 7 8 8 1 8 2 8 3 8 4 8 5 8 6 8 7 8 8 8 9 D 1 D 2 D 3 E 1 E 2 E 3 E 5 OBS501 sensor with the shutter Open ii 6 Device Configuration Utility iii 8 Terminal Mode using 1 and H commands eee cee eeeeeeeeee eee 9 Settings Editor screen i 10 DevConfig Send OS ie 11 Use strain relief to keep stress off the cable and provide extra SEU einaudi 15 Apply tape to protect Sensor iii 16 Secure with hose clamps do not overtighten 16 Place and secure mounting fixture ii 17 Orientation of emitter cone source beam and OBS and sidescatter detector acceptance CONES 18 Normalized response of OBS501 to AMCO Clear turbidity The inset shows the response function of a turbidity sensor to high sediment Co
66. t 5 To query the OBS501 for its current SDI 12 address key in lt enter gt and the OBS501 will respond with its SDI 12 address If no characters are typed within 60 seconds the mode is exited In that case simply enter the command SDI12 again and press lt enter gt 6 To change the SDI 12 address key in aAb lt enter gt where a is the current address from the above step and b is the new address see Figure D 1 The OBS501 will change its address and the datalogger will respond with the new address To exit SDI 12 transparent mode select the Close Terminal button Terminal Emulator Edit Terminal Open CR2XX gt SDI12 SDI12 gt 0 SDI12 gt 0A1 1 SDI12 gt Select Device All Caps Mode C Pause Baud Rate Close Terminal Clear Help Figure D 1 CR200 X example of using the SDI 12 transparent mode to change the SDI 12 address from 0 to 1 D 2 2 CR1000 Datalogger Example 1 Connect an OBSSOI to the CR1000 see Table 7 3 2 Inthe LoggerNet Connect screen navigate to the Datalogger menu and select Terminal Emulator The terminal emulator window will open In the Select Device menu located in the lower left hand side of the window select the CR1000 station 3 Click the Open Terminal button 4 Press the lt enter gt key until the datalogger responds with the CR1000 gt prompt At the CR 000 gt prompt make sure the All Caps Mode box is checked and enter the command SDI12 lt enter gt At the Enter Cx Port 1
67. tivty S mV per mg I 10 0 100 0 1000 0 Median Particle Size D Figure E 1 Normalized sensitivity as a function of grain diameter Figure E 2 shows the difference in apparent turbidity that can result from different ways of disaggregating sediment E 1 Appendix E Factors that Affect Turbidity and Suspended Sediment Measurements 60 Sonic Probe 40 Most Aggressive Sonic Bath Turbidity NTU 20 Hand Shaking Least Aggressive 10 20 30 40 50 Concentration mg r1 Figure E 2 The apparent change in turbidity resulting from disaggregation methods E 2 Suspensions with Mud and Sand As mentioned in Appendix E 1 Particle Size p E 1 light scattering from particles is inversely related to particle size on a mass concentration basis This can lead to serious difficulties in flow regimes where particle size varies with time For example when sandy mud goes through a cycle of suspension and deposition during a storm the ratio of sand to mud in suspension will change A turbidity sensor calibrated for a fixed ratio of sand to mud will therefore indicate the correct concentration only part of the time There are no simple remedies for this problem One solution is to take many water samples and analyse them in the laboratory however this is not always practical during storms when the errors are likely to be largest Do not rely solely on turbidity sensors to monitor suspended sediment particles
68. ts of the OBS501 are typically made by a CR800 CR850 CR1000 or CR3000 datalogger or an RTU device The OBSSOOCBL L Field Cable is used and wired appropriately for the measurement device See Table 8 3 for settings Measurement commands are the same for RS 232 and SDI 12 as shown in Table 8 2 SDI 12 and RS 232 Measurement Commands p 20 Table 8 3 RS 232 Settings Bits Per Second 9600 Flow Control 8 6 Calibration 8 6 1 Turbidity Field recalibration is not recommended and usually not needed until the OBS501 is sent back to Campbell Scientific for the two year service We recommend checking the calibration in the field as described below If a 9 point calibration is needed the OBS501 should be sent to Campbell Scientific to perform the calibration The normalized response of an OBS501 sensor to SDVB turbidity over the range from 0 to 4 000 TU is shown in Figure 8 2 As shown on the inset the response function is contained within region A the linear region of the universal response curve However there is residual nonlinearity that is removed by calibration and by computation of a TU value with a 2nd order polynomial This section explains how to do a turbidity calibration User Manual 0 8 0 6 0 4 E g Normalized OBS 3 Response OPV330 VCSEL 0 2 Turbidity NTU E 0 0 000 Tur bidity TU Figure 8 2 Normalized response of OBS
69. uctions to place the shutter in the normally open mode 6 Specifications Features e Designed to perform better in heavy sediment load environments e Dual backscatter and sidescatter sensors used to measure turbidity e ClearSensor antifouling method for better measurements in biologically active water e Disposable plastic sleeve facilitates cleanup e Optional copper sleeve for additional protection especially for sea water or disposable plastic sleeve facilitates easy cleanup e Compatible with Campbell Scientific CRBasic dataloggers CR6 CR200 X series CR800 series CR 1000 CR3000 and CR5000 Also compatible with Edlog dataloggers CR500 CR510 CR10 X and CR23X Dual Probe Backscatter and 90 degree sidescatter Turbidity Units TU Range 0 to 4000 TU see Section 8 1 Turbidity Units p 17 for information about turbidity units Active and Passive Antifouling Shutter wiper biocide copper optional removable sleeve Accuracy 0 5 TU or 2 of reading whichever is greater Temperature Accuracy 0 3 C 0 to 40 C 7 7 1 Installation Temperature Range Storage Temperature Emitter Wavelength Power Requirements Power Consumption Quiescent Current Measurement Communication Current Shutter Motor Active Current Maximum Peak Current Cycle Time Measurement Time Outputs Submersion Depth Diameter Length Weight Maximum Cable Length User Manual 0 to 40 C non fr
70. ump ahead to Section 9 Maintenance p 31 7 4 2 CRBasic Programming Dataloggers that use CRBasic include our CR200X series CR800 CR850 CR1000 CR3000 and CR5000 dataloggers 13 OBS501 Smart Turbidity Meter with ClearSensor Technology 14 7 4 2 1 SDI 12 7 4 2 2 RS 232 7 4 2 3 Analogue The SDI12Recorder instruction is used to read the OBS501 in SDI 12 mode When using a CR200 X the SDI12Recorder instruction has the following form SDI12Recorder Destination Output String Multiplier Offset For the other CRBasic dataloggers the SDI12Recorder instruction has the following form SDI12Recorder Destination SDIPort SDIAddress SDICommand Multiplier Offset Refer to Appendix B 2 CR1000 SDI 12 Program o B 2 for an example of using this CRBasic instruction More information about using the SDI 12 protocol is provided in Section 8 5 1 SDI 12 p 20 and Appendix D SDI 12 Sensor Support p D 1 The SerialOut instruction sends strings over the Tx COM port and the SerialIn instruction receives strings from the Rx COM port Refer to Appendix B 3 CR1000 RS 232 Program p B 3 for an example of using these CRBasic instructions More information about using the RS 232 protocol is provided in Section 8 5 2 RS 232 p 22 The PortSet instruction is used to open the shutter Either the VoltDiff recommended or VoltSe instruction is used to measure the analogue voltage output Refer to Appendix B
71. vironments Applications include e Compliance with permits water quality guidelines and regulations Determination of transport and fate of particles and associated contaminants in aquatic systems Conservation protection and restoration of surface waters Assess the effect of land use management on water quality Monitor waterside construction mining and dredging operations Characterization of wastewater and energy production effluents Tracking water well completion including development and use 5 2 Backscatter and Sidescatter Sensors The heart of the OBS501 sensor is a near infrared NIR laser and two photodiodes for detecting the intensity of light scattered from suspended particles in water One detector measures the backscatter energy and the second is positioned at 90 degrees to the emitter to measure the sidescatter energy Backscatter and sidescatter sensors have unique strengths and weaknesses Generally speaking backscatter provides high range HR measurements and sidescatter provides low range LR measurements The OBS501 combines both in one sensor to provide unequalled performance in a field turbidity sensor With their unique optical design U S Patent 4841157 backscatter sensors perform better than most in situ turbidity monitors in the following ways e Measure turbidity to 4000 TU compared to 1200 TU typically for sidescatter sensors e Insensitivity to bubbles and organic matter e Ambient light rejection
72. when particle size or composition is expected to change with time at a monitoring site E 3 Particle Shape Effects E 2 In addition to size and flocculation aggregation particle shape has a significant effect on the scattering intensity from a sample and calibration slope of a turbidity sensor As the graph in Figure E 3 shows plate shaped particle clay mineral particles for example backscatter light about ten times more efficiently than spherical particles while angular shapes have intermediate scattering efficiency Turbidity sensors are very sensitive to shape effects and this makes it very important to calibrate with material from the monitoring site It is also essential that particle shape remains constant during the monitoring period Appendix D SDI 12 Sensor Support OBS 3 1 Plates Cubes e a Spheres Relative Scattering Intensity 0 01 0 20 40 60 80 100 120 140 160 180 Scattering Angle Figure E 3 Relative scattering intensities of grain shapes E 4 High Sediment Concentrations At high sediment concentrations particularly in suspensions of clay and silt the infrared radiation from the emitter can be so strongly attenuated along the path connecting the emitter the particle and the detector that backscatter decreases exponentially with increasing sediment concentration For mud this occurs at concentrations greater than about 5 000 mg l Figure E 4 shows a calibration in which sediment concentratio

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