Manual (RT) - Communication Technology
Contents
1. the SBE 35RT finishes sampling 1 1 ncycles 2 seconds the SBE 35RT will ignore the second bottle confirmation 7 After the CTD cast run TERM 35 Press Function Key 9 to upload the data The data file will be stored with a ASC extension 8 Run DATCNV In Water Bottle Set Up select scans marked with bottle confirm bit as the source of scan range Set offset to 0 0 and duration 1 1 ncycles 11 5 Measurement Cycle Section 5 Measurement Cycle This section provides description of measurement cycle for the SBE 35 RT The SBE 35RT determines temperature by applying a 1 2 kHz AC excitation to a reference resistor zero ohms and an ultrastable thermistor and digitizing the output from each with a 20 bit delta sigma A D converter The reference resistor is a hermetically sealed VISHAY VHP202K inside a temperature controlled oven The switches are All Position mercury wetted reed relays with a stable contact resistance AC excitation and ratiometric comparison using a common processing channel removes measurement errors due to parasitic thermocouples offset voltages leakage currents and gain errors Maximum power dissipated in the thermistor is 5e 7 watts NR output from the reference resistor NZ output from zero ohms NT output from the thermistor Output from the sensor 1048576 NT NZ NR NZ Each acquisition cycle is select zero ohms wait 0 1 seconds for the output to stabilize averag2. 3 1047565 1047566 1047554 1047555 1047551 752453 3 15 31 27 753130 0 752457 4 15 31 21 753129 0 752459 1 15 32 18 753129 5 752459 9 19 30 21 753129 5 752451 2 13 34 28 753129 6 752451 4 17 30 27 753129 2 752449 1 14 27 21 753129 2 3 SBE 35 RT Commands run Sample continuously compute temperature do not store samples The output format is the same as in page 8 but with computed temperature added in the eighth column Although the total time per measurement cycle is 1 1 ncycles seconds the time between sample updates is 1 1 ncycles 2 7 seconds The extra time is spent converting the measured values to computed temperature and transmitting the data at 300 baud DATA UPLOAD dd Dump all the data ddB E Dump scans B through E The format is column 1 sample number column 2 3 date and time DD MMM YYYY HH MM SS column 4 bottle position column 5 maximum minimum thermistor value column 6 sensor output n column 7L computed temperature ITS 90 A sample output with the SBE 35RT taking data in room ambient air is 1 30 Sep 1998 16 15 13 bn 8 diff 19 val 509867 0 t90 8 752364 2 30 Sep 1998 16 15 41 bn 6diff 21 val 509867 4 t90 8 752342 0 30 Sep 1998 10 29 29 bn 1 30 Sep 1998 10 31 00 bn 2 30 Sep 1998 10 31 30 bn 3 30 Sep 1998 10 32 00 bn 4 30 Sep 1998 10 32 30 bn 5 30 Sep 1998 10 33 00 bn diff 268 val 278061 1 diff 84 val 277430 6 diff 140 val 277357 8 diff 357
3. SBE 35 RT Digital Reversing Thermometer User s Manual Sea Bird Electronics Inc 1808 136 Place NE Bellevue Washington 98005 USA Tel 425 643 9866 Fax 425 643 9954 Limited Liability Statement Extreme care should be exercised when using or servicing this equipment It should be used or serviced only by personnel with knowledge of and training in the use and maintenance of oceanographic electronic equipment SEA BIRD ELECTRONICS INC disclaims all product liability risks arising from the use or servicing of this system SEA BIRD ELECTRONICS INC has no way of controlling the use of this equipment or of choosing the personnel to operate it and therefore cannot take steps to comply with laws pertaining to product liability including laws which impose a duty to warn the user of any dangers involved in operating this equipment Therefore acceptance of this system by the customer shall be conclusively deemed to include a covenant by the customer to defend indemnify and hold SEA BIRD ELECTRONICS INC harmless from all product liability claims arising from the use or servicing of this system Table of Contents Section 1 Introduction About this manual Section 2 Communication with the SBE 35 RT Section 3 SBE 35 RT Commands Section 4 Operating the SBE 35 RT Use with SBE 911plus and Carousel Water Sampler Use with SBE 19 or 25 CTD and Carousel Water Sampler Section 5 Measurement Cycle Section 6 Calibrat
4. ally mapped sensor positions is better than 0 0001 C Sea Bird s new metrology laboratory underpins the new temperature calibration baths Following consultation with the U S National Institute of Standards and Technology the met lab was configured to achieve temperature precision of 50 uK and accuracy of 0 0005 C To obtain this performance premium primary references including four Jarrett water triple point cells with maintenance bath and an Isotech gallium melt cell are operated in conjunction with two YSI 8163 standards grade platinum resistance thermometers and an ASL F18 Automatic Temperature Bridge 13 References References Steinhart J S and Hart S R 1968 Calibration Curves for Thermistors Deep Sea Research 15 p 497 Bennett A S 1972 The Calibration of Thermistors over the Temperature range 0 30 C Deep Sea Research 19 p 157 14
5. e thermal dissipation from electronic instruments The SBE 35RT has a time constant of 0 5 seconds so it will lag the SBE 3 if temperature is changing during the measurement internal A first order correction is Determine the temporal gradient during the measurement interval from the secondary SBE 3 temperature data in the ROS file g temperature gradient C s Gradient corrected SBE 35RT temperature SBE 35RT measured temperature 0 5 g Use with a SBE 911plus and Carousel Water Sampler 1 Connect the SBE 11plus deck unit modem channel to a PC using a straight through serial cable P N 80073 Connect the SBE 35RT to the SBE 9plus and Carousel water sampler using cable Y cable SBE 171220 DWG 32208 The three arms of the Y cable are labeled SBE 9 SBE 32 and SBE 35RT Connect each arm to the proper device Power the SBE 9plus with the 11plus deck unit Run TERM 35 and send the display status command DS to verify communication with the SBE 35RT If no reply is received press lt F2 gt to bring up the setup form select communication set up and check the COMM port setting In addition check that the bottle confirm interface is correct for the application If not type interface and either 91 1plus or 32 serial Set samplenum to zero and run SEASAVE to acquire the CTD cast The SBE 35RT will take a sample each time it receives a bottle confirmation and store the data in EEPROM If a second bottle is fired bef
6. e for 0 267 seconds this is NZ select reference resistor wait 0 1 seconds for the output to stabilize average for 0 267 seconds this is NR select thermistor wait 0 1 seconds for the output to stabilize average for 0 267 seconds this is NT The total time per cycle is 1 1 second The number of the above acquisition cycles per measurement is programmable Increasing the number of cycles per measurement increases the time to acquire the sample while reducing the RMS temperature noise from the sensor The following RMS noise values are typical for a SBE 35RT in a triple point of water cell Necycles Acquisition Time Standard Deviation C 8 8 8 seconds 0 000029 32 35 2 seconds 0 000014 Temperature is computed using the Steinhart Hart polynomial for thermistors Steinhart and Hart 1968 Bennett 1972 as follows n is the output from the SBE 35RT toon 1 0 273 15 a0 alln n a2in n a3ln n adin n top slope X too offset deg C ITS 90 Carrying the polynomial to fourth order captures the non linearity of the SBE 35RT thermistor output to better than 0 0001 C 12 6 Calibration Section 6 Calibration SBE 35RTs are calibrated to ITS 90 temperature using Sea Bird s computer controlled calibration bath Extremely well insulated the baths provide a uniform toroidal circulation yielding an overall transfer accuracy against an SPRT within 0 0002 C Repeatability at each of twelve individu
7. each time a bottle fire confirmation is received and stores the value in EEPROM Each stored value contains the time of day and the bottle position in addition to the temperature data to facilitate comparison of the SBE 35RT record with CTD and water bottle data The SBE 35RT can use the built in CTD modem channel for two way communications It is not necessary to change cable connections to communicate and retrieve data from the SBE 35RT Supplied with the SBE 35RT is a powerful software package SEASOFT which enables the user to communicate retrieve data and to calculate and display temperature SEASOFT as supplied is designed to run on IBM XT AT 386 486 Pentium or compatible computers A separate software manual contains additional information on the setup and use of SEASOFT 2 Communication with the SBE 35 RT Communication with the SBE 35 RT Use the program TERM35 supplied with the SBE 35RT or any other terminal program set to 300 baud 8 data bit no parity to communicate with the SBE 35RT For lab use 1 Connect the SBE 35RT to a SBE 90248 opto box using cable P N 80555 The opto box isolates power to the SBE 35RT and buffers the serial communication lines in order to minimize noise input to the SBE 35RT from external sources 2 Connect the 90248 to a serial port on a PC with a straight through cable P N 80677 The SBE 35RT communicates at 300 baud 8 data bits no parity Note The orange LED will flash wh
8. en the SBE 35RT transmits The green LED will flash when the PC transmits 3 The SBE 35RT will transmit SBE 35RT wake up three seconds after the 90248 opto box is powered on 3 SBE 35 RT Commands Section 3 SBE 35 RT Commands This section describes the commands associated with TERM35 as part of SEASOFT Command Descriptions STATUS ds dc Display Status A typical reply would be SBE35 V 2 0 SERIAL NO 0013 01 Oct 1998 15 56 52 number of measurement cycles to average 8 number of data points stored in memory 2 bottle confirm interface SBE 911plus S gt Display Calibration Coefficients A typical reply would be SBE35 V 2 0 SERIAL NO 0013 09 apr 97 A0 5 156252707e 03 A1 1 430180396e 03 A2 2 092145355e 04 A3 1 156278215e 05 A4 2 446454055e 07 SLOPE 1 000000 OFFSET 0 000000 S gt SET UP ncycles N interface 91 1plus interface 32serial samplenum N Set the number of measurement cycles per acquisition to N Each acquisition cycle is 1 1 seconds in duration In a thermally quiet environment the temperature noise standard deviation is 0 000029 sqrt 8 ncycles C SBE 35RT is used with a SBE 91 1plus CTD and Carousel SBE 35RT is used with a SBE 19 or 25 CTD and Carousel Set the sample number to N Set N to 0 at the beginning of a cast after all previous data has been downloaded from the SBE 35RT 3 SBE 35 RT Commands DDMMYY ddmmyy Set curr
9. ent day month and year This command must be followed by HHMMSS command to set the time MMDDYY mmddyy Set current month day and year This command must be followed by HHMMSS command to set the time DDMMYY and MMDDYY commands are equivalent Either one can be used to set the date HHMMSS hhmmss Set the current hour minute and second Example To set the current date and time to 10 January 1997 12 00 00 MMDDY Y 011097 HHMMSS 120000 or DDMMYY 100197 HHMMSS 120000 ACQUISITION Bottle Confirm ts cal Whenever the SBE 35RT receives a valid bottle confirmation sequence a character with decimal value 6 followed by a character with decimal value greater than 48 and less than 84 it takes a measurement ncycles in duration and stores the date output in time bottle number maximum minimum thermistor value and sensor EEPROM Take one sample and store it in EEPROM Sample continuously do not compute temperature do not store samples Output Format column 1 column 2 column 3 column 4 column 5 column 6 column 7 zero value reference resistor value thermistor value maximum minimum zero value maximum minimum reference resistor value maximum minimum thermistor value sensor output n A typical output with the SBE 35RT in a triple point of water cell with the number of cycles per measurement 16 is 197 21 197 87 197 64 198 08 197 73 197 91 197 71 1047557 104756
10. ion References 14 Warranty Policy Service Information Calibration Certificates 1 Introduction Section 1 Introduction About this manual How to contact Sea Bird This section includes contact information and manual version number This manual is to be used with the SBE 35 RT Digital Reversing Thermometer It is organized to guide a user from installation through operation and data collection We ve included command descriptions measurement cycle and calibration information If you have any questions do not hesitate to contact us at the numbers below Manual Version 005 03 30 99 Sea Bird Electronics Inc 1808 136 Place Northeast Bellevue Washington 98005 USA Telephone 425 643 9866 Fax 425 643 9954 E mail seabird seabird com Website http www seabird com Our business hours are Monday Friday 0800 to 1800 Pacific Standard Time 1600 to 0200 Universal Time Except from April to October when we will be on summer time 1500 to 0100 Universal Time Section 2 2 Communication with the SBE 35 RT Communication with the SBE 35 RT System Description This section describes the function and features of the SBE 35 RT The SBE 35RT is an accurate ocean range temperature sensor that can act as a stand alone substitute reversing thermometers When used with a SBE 91 plus SBE 19 or SBE 25 CTD and Carousel water sampler the SBE 35RT makes a temperature measurement
11. ore the SBE 35RT finishes sampling 1 1 ncycles 2 seconds the SBE 35RT will ignore the second bottle confirmation After the CTD cast run TERM 35 Press Function Key 9 to upload the data The data file will be stored with a ASC extension Run DATCNV In Water Bottle Set Up select scans marked with bottle confirm bit as the source of scan range Set offset to 0 0 and duration 1 1 ncycles 10 4 Operating the SBE 35 RT Use with a SBE 19 or 25 CTD and Carousel Water Sampler 1 Connect the SBE 33 deck unit modem channel to a PC using a straight through serial cable P N 80073 2 Connect the SBE 35RT to the Carousel water sampler using cable SBE 171221 DWG 32209 This is not a straight through cable Connect the end labeled SBE 35RT to the SBE 35RT and the end labeled SBE 32 to the Carousel 3 Power the Carousel with the SBE 33 deck unit 4 Run TERM 35 and send the display status command DS to verify communication with the SBE 35RT If no reply is received press lt F2 gt to bring up the setup form select communication set up and check the COMM port setting In addition check that the bottle confirm interface is correct for the application If not type interface and either 91 Iplus or 32serial 5 Set samplenum to zero and run SEASAVE to acquire the CTD cast 6 The SBE 35RT will take a sample each time it receives a bottle confirmation and store the data in EEPROM If a second bottle is fired before
12. val 277163 3 diff 367 val 277055 7 diff 409 val 276487 1 NNnNRWN KR CALIBRATION COEFFICIENTS caldate sssss set the calibration date to sssss factory programmed ta0 F set AO coefficient F factory programmed tal F set Al coefficient F factory programmed ta2 F set A2 coefficient F factory programmed ta3 F set A3 coefficient F factory programmed ta4 F set A4 coefficient F factory programmed offset F set the offset to F slope F set the slope to F TESTING rtctest Test battery backed static RAM in the real time clock module eetest Test the EEPROM memory Allow 30 seconds for this test to complete This command will destroy all data stored in the EEPROM and will overwrite the calibration coefficients Both the rtctest and eetest overwrite data stored in the SBE 35RT SRAM Re set the date time and number of cycles to average after running these commands 4 Operating the SBE 35 RT Section 4 Operating the SBE 35 RT Operation This section will describe SBE 35 RT operation with Sea Bird CTD s and the Carousel Water Sampler At sea the SBE 35RT can act as a stand alone substitute for a reversing thermometer recording temperature with each bottle closing In this application the SBE 35RT is mounted in a secure area on the water sampler frame where the ocean water flushes freely and there is minimal contamination from the passive thermal mass of the metal frame or activ
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