Model 2000 Manual
Contents
1. ELO MAT E MODEL 2 PORTABLE FLOWMETER INSTRUCTION MANUAL MODEL 2000 INSTALLATION AND OPERATIONS MANUAL DECEMBER 1990 Marsh McBirney Inc 4539 Metropolitan Court Frederick Maryland 21704 9452 301 874 5599 800 368 2723 FAX 301 874 2172 www marsh mcbirney com PN 105 0003 01 Rev D 11 00 CONTENTS General DOSCHIDHOTN gyd Cd Ua 1 Theory 5 Oper auon na mes ad a ag TO dU CCR eld 2 Design ncu asset tes qe dy a o i GC fy Fn dd dyg dydd 3 Opera su FR Of DG RO 4 Reale Dime Operatine Fod dydd ates fac tdv ev dw OG 4 Display GO O dd yng Cd 4 Units Of Measurement Beeper Se dd Fod 5 Fixed Point Averages lume Constant ne CD GL FOCS 5 BPA NO Y Fd Fydd 5 un da odd a 6 TIME FFR NR HYNN DY WN 6 Display ec 7 Storme Velocity Reading S iiber oce tp Fd Nad 7 Recall Oper atin Moder ae au 8 Ad MT dd GER GSG RES SF OY YNE dd ONR DF FE dd do Ed YR Ff Fod 8 Gra TTD 8 Z2. Clear display function The clear display function clears the display and restarts the filtering Data storage and recall ability There are 19 memory locations in which to store and recall velocity measurements Unit of measurement selection The meter can be switched between English ft s and metric m s units of measurement Selectable filtering modes for display output Fluid dynamics near the sensor electrodes may cause slightly noisy readings The output can be stabilized by averaging the velocities over a fixed time period or by a software algorithm that mimics an RC time constant OPERATION The Model 2000 has two operating modes Real Time and Recall In the Real Time operating mode Real Time velocities from the sensor are displayed In the Recall operating mode velocities from memory aredisplayed Comment In the Recall mode the time bar will be stationary Real Time Operating Mode The unit will always power up in the real time operating mode From the real time mode you can change the filter value store readings in memory turn the beeper on or off alternate between feet per second ft s and meters per second m s alternate between fixed point averaging and time constant filtering and switch to the recall operating mode Display ON Seguence When the unit is turned ON the display output seguence is as follows Software version number This is the Model 2000 operating software that was burned into the electr
3. 5655 814 3250 565 5034 45 2215 153 8512 9428 5824 838 6420 582 3902 46 2280 158 3212 3527 5993 863 0080 599 3111 AT 2344 162 7985 3627 6163 887 4133 616 2592 48 2409 167 2811 3727 6332 911 8480 633 2277 49 2473 171 7673 3827 6502 936 3024 650 2100 150 2938 176 2553 3927 6672 960 7664 667 1989 2 3 2 4 Table I Continued K Flow Unit Mulitiplier L D MGD GPM CFS CMM CMD LPM 51 2603 180 7433 4027 6842 985 2306 684 1879 52 2667 185 2295 4127 7012 1009 6850 701 1701 53 2732 189 7121 4227 7181 1043 1200 718 1385 54 2796 194 1894 4327 7351 1058 5250 735 0869 55 2861 198 6594 4426 7520 1082 8910 752 0076 96 2925 203 1204 4526 7689 1107 1080 768 8945 57 2989 207 5706 4635 7857 1131 4660 785 7401 58 3053 212 0080 4724 8025 1155 6540 802 5377 99 3117 216 4309 4822 8193 1179 7630 819 2801 60 3180 220 8374 4920 8360 1203 7830 835 9605 61 3243 225 2255 9018 8526 1227 7030 852 5715 62 3306 229 5934 9115 8691 1251 5120 869 1057 63 3369 233 9392 5212 8856 1275 2010 885 5560 64 3431 238 2607 5308 9019 1298 7580 901 9149 65 3493 242 5560 5404 9182 1322 1710 918 1745 66 3554 246 8232 5499 9343 1345 4320 934 3275 67 3615 251 0600 5594 9504 1368 5260 950 3654 68 3676 255 2643 5687 9663 1391 4440 966 2805 69 3736 259 4340 5780 9821 1414 1730 982 0645 70 3795 263 5668 5872 9977 1436 7010 997 7090 71 3854 267 6604 9963 1 0132 1459 0150 1013 2050 72 391
4. _ SENSOR Figure 4 Sensor disconnect Only use the NiCad batteries that are supplied with the AC power option If batteries other than 4 4 Ah nicads are used they may rupture and damage the unit or present a hazard to the operator Figure 5 AC Power Adapter 14 The flowmeter is shipped with 2 D Size Sanyo KR4000 D NiCad batteries installed that should be left in the unit when external power is being used They serve as a filter and provide backup power if the main power fails A well isolated AC power adapter Figure 5 serves as a battery charger and external power source The NiCads take about 14 hours to charge Power reguirements are 300 mA 3 for wet sensor mr 100 mA 3 V for dry sensor Carrying Case d The carrying case for the Model 2000 Figure 6 is padded nylon case with two compartments and shoulder strap The back compartment is for M the meter and the front compartment is for the y 7 sensor and cable The sensor compartment is made of nylon mesh which lets air circulate through the sensor compartment y i Figure 6 Carrying Case SENSORS The Model 2000 can be configured with an open channel velocity sensor a one inch full pipe velocity sensor or a two inch full pipe velocity sensor The open channel velocity sensor is the standard configuration Open Channel Velocity Sensor The front of the open channel velocity sensor is
5. if the FPA is set to 10 seconds the display is updated once every ten seconds The FPA display will have a horizontal time bar under the velocity output The time bar provides an indication as to the amount of time left until the display is updated ABAAA A Ha PERIOD rc The display will show the letters rC when you first switch to the time constant mode The display will start with unfiltered full scale velocities These readings are accurate but may bounce around slightly As the filtering takes effect the readings will settle out It takes five time constants to get to maximum filtering There is no time bar on the rC display because the display is continually up dated fa 2 rf Hie ns FPA rC Time The FPA and time is specified in seconds The f key increments time and the 4 key decrements time The display will show the FPA rC length in seconds After you have reached the desired setting wait and the display will automatically switch to velocity Comment Limits are 2 120 seconds for FPA and 2 30 seconds for rC Changing FPA and rC time restarts the filtering im AM A 2 Lh Clearing the Display The clear function will clear the display and restart the filtering To clear the display press the ON C key The display will blank out for a second and then restart to output velocity readings aA AA A A eb brs ic PERIOD NEN
6. round with three electrodes A mounting hole is in n THUMBSCREW back and a thumbscrew is on top Figure 7 The front of the sensor must pointed upstream and the Jl JR f electrodes must be in contact with the flow to get eL cd 7 PL goodreadings k 9 x aa Comment kJ LA B MAU LS The electrodes on all sensors must be kept free from nonconductive coatings such oil and grease an ELECTRODES i The open channel velocity sensor shape produces a MM cosine response which greatly reduces errors due to TING sensor positioning For example if the front of the sensor is pointed away from the flow at a 10 angle Figure 7 Open Channel Velocity the cosine of 10 is 0 98480 This is only 1 5 Sensor lower than the actual velocity 15 Full Pipe Velocity Sensor The Model 2000 can be configured with either a one inch full pipe velocity sensor or a two inch full pipe velocity sensor Figure 8 The installation instructions for the full pipe sensors are contained in the manuals titled One Inch Full Pipe Sensor Installation and Two Inch Full Pipe Sensor Installation The S sensor disconnect is required when the unit is configured with a full pipe sensor Ground Button Velocity Electrodes Figure 8 Full Pipe Velocity Sensor SENSOR MOUNTING CONFIGURATIONS Universal Sensor Mount Pole The sensor can be attached to different size po
7. 0388 26 9294 0600 1019 146 7919 101 9388 14 0432 29 9967 0668 1135 163 5116 113 5497 15 0477 33 1571 0739 1255 180 7393 125 5134 16 0524 36 4056 0811 1378 198 4467 137 8102 A7 0572 39 7374 0885 1504 216 6081 150 4223 18 0621 43 1480 0961 1633 235 1995 163 3330 19 0672 46 6334 1039 1765 254 1985 176 5267 20 0723 50 1898 1118 1900 273 5844 189 9892 21 0775 53 8135 1199 2037 293 3373 203 7064 22 0828 57 5012 1281 2177 313 4387 217 6657 23 0882 61 2496 1365 2319 333 8710 231 8548 24 0937 65 0555 1449 2463 354 6172 246 2619 25 0992 68 9161 1535 2609 375 6613 260 8759 26 1049 72 8286 1623 2757 396 9880 275 6861 27 1106 76 7901 A711 2907 418 5825 290 9823 28 1163 80 7982 1800 3059 440 4305 305 8545 29 A222 84 8503 1890 3212 462 5182 321 1932 30 1281 88 9439 1982 3367 484 8325 336 3892 31 1340 93 0767 2074 3523 507 3605 352 3337 32 1400 97 2464 2167 3681 530 0894 368 1176 33 1461 101 4507 2260 3840 553 0071 384 0327 34 1522 105 6875 2355 4001 576 1017 400 0706 35 1583 109 9546 2450 4162 599 3618 416 2234 36 1645 114 2500 2545 4325 622 7757 432 4831 137 1707 118 5715 2642 4488 646 3325 448 8419 138 1770 122 9172 2739 4653 670 0208 465 2922 39 1833 127 2851 2836 4818 693 8301 481 8265 40 1896 131 6733 2934 4984 717 7501 498 4375 41 1960 136 0797 3032 15151 741 7607 515 1178 42 2023 140 5026 3130 5319 765 8788 531 8603 43 2087 144 9400 3229 5487 790 0673 548 6578 44 2151 149 3902 3328
8. 4 y Storing Velocity Readings There are 19 memory locations in which velocity readings can be stored To store a reading press the STO key when the desired velocity is displayed The unit will store the reading and automatically increment to the next empty location The memory location shown on the display is where the present reading will be stored No memory locations are shown until after the first reading has been stored Comment Except for the beeper symbol the STO function will store the display as you see it Turning the unit off or changing batteries will not affect the memory If you want to measure a prior location again you need to switch to the recall mode with the RCL key Go back to the prior location with the f key Switch to the real time mode with the RCL key and when you get a good velocity reading store it with the STO key The reading is stored and the unit advances to the next empty memory location dae 2A PERICO REENEN mil Recall Operating Mode The recall operating mode outputs the velocity readings that have been stored in memory The recall mode is indicated by a blinking memory location number and always starts at location one To switch to the recall mode press the RCL key The memory location and the velocity stored in that location 1 shown on the display Increment and decrement through the locations with the and keys respet tively With the exce
9. 5360 1334 4000 RECTANGULAR CHANNELS Flow in rectangular channels is calculated by the following Determine Uwith the 2 4 8 method as described on Page 1 3 For channel widths of six feet or larger use the 2 6 8 method as described on Page 2 6 for rivers and streams Velocity units must be in ft sec e Calculate the cross sectional area in ft by Depth of Flow in 12 x Channel Width in 12 Calculate flow by U x Cross sectional Area The result should be a flow rate in ft sec CFS You can convert this to other flow units with the flow unit conversion multipliers in Table III on page 2 7 Example What is the flow in a channel 24 inches wide with a 10 inch deep flow Solution Velocity measured at 2 1 5 ft sec 4 1 7 ft sec 8 1 8 ft sec e 1 5 1 8 2 1 65 ft sec U 1 65 1 7 2 1 67 ft sec e From Table II on Page 2 5 10 in 0 83 ft Area 0 83 ft x 2 ft 1 66 ft Flow 1 67 ft sec x 1 66 ft 2 77 ft sec From Table III on Page 2 7 64632 x 2 77 1 7903 MGD Table II Inch to Feet Conversion IN 0 50 1 00 1 50 2 00 2 50 3 00 3 50 4 00 0 04 0 08 0 13 0 17 0 21 0 25 0 29 0 33 450 5 00 5 50 6 00 6 50 7 00 7 50 8 00 0 37 0 42 046 0 50 054 0 58 0 62 0 67 8 50 9 00 9 50 10 00 10 50 11 00 11 50 12 00 071 0 75 0 79 0 83 087 0 92 0 96 1 00 2 5 RIVERS AND STREAMS You will need to divide the width of t
10. Caution on Page 14 before using NiCad batteries Self Discharge in Storage Alkaline batteries will lose approximately 5 to 10 of their charge per year NiCad batteries will lose about 1 to 2 of their charge per day Therefore NiCad batteries should be charged shortly before use Low Battery Flag A low battery flag is displayed when the battery voltage drops below a certain value The amount of time the batteries will last after the flag is displayed can vary from an hour alkaline to 15 minutes NiCad batteries The unit will shut itself off if the voltage drops too low 13 OPTIONS Sensor Disconnect sensor cable can be disconnected from the flowmeter with the sensor disconnect option To disconnect the sensor pull the latch release Figure 4 toward the sensor cable To connect the cable align the latch alignment marks and push the connector together Comment If you change sensors check the zero Page 9 Power In Signal Out Connector Except for being smaller in size the power in signal out connector Figure 4 operates the same as the sensor disconnect The connection to the output signal is made on a terminal strip that is attached to the AC power adapter The signal can be output to external recording devices Output impedance 1 1 Output signal is 0 1 V 1 ft sec or 0 1 V 1 m sec Maximum scale is 2 volts CAUTION LATCH i gt ALIGNMENT MARKS LATCH RELEASE
11. Double End Hanger The sensor is mounted to the standard wading rod with a double end hanger Figure 11 Slide the wading rod through the hole in the hanger and hand tighten the locking screw on the side Insert the mounting shaft on the hanger into the hole in back of the sensor Then hand tighten the thumbscrew on top of the sensor The thumbscrew must be seated in the groove on the shaft so make sure the mounting shaft is completely inserted into the hole on the sensor 17 Top Setting Wading Rod Two accepted methods for determining mean velocities of flows are as follows 1 Measure the velocity at 60 of the depth from the top and use this as the mean 2 Measure the velocity at 2090 and 8090 of the depth from the top Use the average of these velocities as the mean The purpose of the top setting wading rod Figure 12 is to conveniently set the sensor at 20 60 or 80 of total depth The total depth can be measured with the depth gauge rod Each single mark represents 0 10 foot each double mark represents 0 50 foot and each triple mark represents 1 00 foot To set the sensor at 60 of the depth line up the foot scale on the sliding rod with the tenth scale on the top of the depth gauge rod If for example the total depth is 2 7 feet then line up the 2 on the foot scale with the 7 on the tenth scale To set the sensor at 20 of the depth multiply the total depth by two and repeat the above procedure In the above exam
12. ON and try again A d 4 AA A d u 4M 2M SN jc ERRORS The purpose of displaying errors is to alert the user of possible problems with either the unit or applica tion Errors can be displayed as messages or numerical codes There are three error messages and five numerical codes Comment With the exception of Err 2 error codes freeze the display Turn the unit OFF then back ON to clear the display If after corrective action the error still exists call the factory Error Messages LOW BAT ri Low Bat Indicates low batteries Page 13 5 Replace the batteries Page 12 PERIOD Noise Indicates excessiveelectricalnoiseis present in the flow which will interfere with normal operation This will cause the display to blank out Comment The noise flag usually comes on for few a seconds after the sensor is submerged even though there is no noise present This is normal Con Lost Indicates that either the sensor elec trodes are out of the water or they have become coated with oil or grease After 5 minutes the unit will turn itself OFF If the electrodes are coated clean them EG Page 12 10 Error Codes Error 1 Error 2 Error 3 Error 4 Error 85 Problem with sensor drive circuit Check sensor disconnect rr ce P Memory full error Memory must be cleared before another reading can be stored Incorrect zero adjust start sequ
13. as follows Lightweight 3 Ib 9 oz with sensor and 20 ft of cable water resistant and rugged The case is made of a high impact molded material which protects the electronics from wet environments and accidental submersions Digital filtering The sensor electronics uses digital filtering This does a better job than analog filtering in rejecting electrical noise that may be present in the flow Noise flag If there is enough electrical noise present in the flow to interfere with normal operation the display will blank out and the noise flag is displayed Conductivity lost detection A conductivity lost flag is displayed and the velocity readings are blanked out when conductivity lost is detected Conductivity lost is usually caused by the sensor being out of the water Dry sensor power down The unit stops driving the sensor five seconds after conductivity lost is detected This results in a 66 reduction in power consumption which conserves battery life If the sensor is dry for more than 5 minutes the unit will turn itself OFF Automatic shut off After five minutes of conductivity lost the unit will shut itself off thus con serving battery life Low battery flag A low battery flag is displayed when the battery voltage drops below a certain value The amount of time the batteries will last after the flag is displayed can vary from an hour alkaline to 15 minutes nicads The unit will shut itself off if the voltage drops too low
14. 3 271 7125 6054 1 0285 1481 1030 1028 5440 73 3970 275 7206 6143 1 0437 1502 9510 1043 7160 74 4027 279 6822 6231 1 0579 1524 5460 1058 7120 75 4084 283 5946 6319 1 0735 1545 8720 1073 5220 76 4139 287 4553 6405 1 0881 1566 9170 1088 1370 77 4194 291 2612 6489 1 1025 1587 6630 1102 5440 78 4248 295 0096 6573 1 1167 1608 0950 1116 7330 79 4301 298 6972 6655 1 1307 1628 1970 1130 6920 80 4353 302 3210 6736 1 1444 1647 9500 1144 4090 81 4405 305 8774 6815 1 1579 1667 3360 1157 8720 82 4455 309 3629 6893 1 1711 1686 3350 1171 0660 83 4505 312 7735 6969 1 1840 1704 9260 1183 9760 84 4552 316 1053 7043 1 1966 1723 0880 1196 5890 85 4599 319 3538 7115 1 2089 1740 7950 1208 8860 86 4644 322 5143 7186 1 2208 1758 0230 1220 8490 87 4688 325 5815 7254 1 2325 1774 7430 1232 4600 88 4731 328 5500 7320 1 2437 1790 9240 1243 6970 89 4772 331 4135 7384 1 2545 1806 5330 1254 5360 90 4812 334 1650 7445 1 2650 1821 5310 1264 9520 91 4850 336 7967 7504 1 2749 1835 8760 1274 9140 92 4886 339 2997 7560 1 2844 1849 5200 1284 3890 93 4920 341 6636 7612 1 2933 1862 4060 1293 3370 94 4952 343 8759 7662 1 3017 1874 4650 1301 7120 95 4981 345 9216 7707 1 3095 1885 6160 1309 4560 96 5008 347 7815 7749 1 3165 1895 7540 1316 4960 97 9032 349 4297 7785 1 3277 1904 7390 1322 7350 98 5052 350 8287 7816 1 3280 1912 3650 1328 0310 99 9068 351 9145 7841 1 3321 1918 2840 1332 1410 1 00 5076 352 5112 7854 1 3344 1921
15. LEVEL Circular Conduits Measure the inside diameter of the conduit Measure distance D Figure 1 4 D Subtract D from the inside diameter of the vf conduit for the depth of flow This eliminates the problem of the ruler interfering with the liquid Comment The level measurement and the velocity profile must be on the same plane for proper application of the continuity equation Figure 1 5 Level Measurement YES PLANE OF PROFILE X PLANE OF PROFILE Em Figure 1 6 Location of Level Measurement 1 5 SECTION II CALCULATING FLOW CIRCULAR CONDUITS To calculate flow in circular conduits you need The mean velocity Ufrom Section I The depth of flow at the time of profile The inside diameter of the conduit Outline Calculating flow is outlined as follows Calculate the level to diameter ratio L D Identify the flow unit multiplier K Table I Pages 2 3 and 2 4 Sguare the diameter in feet Calculate flow Calculate the Level Diameter Ratio L D Ratio L D Where L is depth of flow in inches at time of profile D isinside diameter in inches L D isthelevel diameterratio Identify Flow Unit Multiplier K L D Ratio in Table I on Pages 2 3 and 2 4 Where K istheflow unit multiplier Find the appropriate L D ratio in the L D column and move to the right to the desired units column to get the proper flow unit multiplier Comment The flow unit multiplier in Table I
16. ST FIT V Y CURVE E L AL REGION i N 3 e H E i 5 2 OUTLIER i 0 1 2 3 4 5 6 VELOCITY FT SEC Figure 3 1 Best Fit Curve Comment The 4 3 ft sec velocity at the 3 inch position is outside the best fit curve region and is ignored This is called an outlier 3 2 The 2 4 8 Method POSITION VELOCITY 2 7 1 4 5 4 ft sec 7 2 8 Ww 5 5 ft sec 8 x 7 3337 x 5 35 ft sec 5 4 5 35 2 5 37 ft sec U 5 37 5 5 2 5 44 ft sec The 4 Method The velocity at the 4 position 5 5 ft sec U 5 5 ft sec The 0 9 x Vmax Method Vmax 5 5 ft sec U 0 9 x 5 5 4 95 ft sec The 2 D Method Average all velocity measurements Remember to include the two corner measurements and discard any outliers U 4 8 ft sec The VPT Method This method requires a computer program If you have this program enter the velocity measure ments from the center line profile Discard any outliers U from VPT program 5 32 ft sec Average U An overall U can be calculated by averaging the values from the different methods 5 44 5 5 4 95 5 0 5 32 5 5 24 ft sec Comment If the profile is not symmetrical then the results from the 9 x Vmax and 2 D methods may vary greatly from the VPT 2 4 8 and 4 methods 3 3 OF DEVIATION We calculate the 96 of deviation between the average and high U and the average and low U We discard any U that has a deviation greater th
17. an 1096 from the average U of Deviation Between High U 5 5 ft sec and Average U lt 5 5 5 2 deviation x 100 5 7 5 24 of Deviation Between Low U 4 8 ft sec and Average U 5 2 4 8 deviation 52 x 100 7 790 Since the no deviation is greater than 1046 from the average U all the values are useable 3 4
18. ar CondimtS dy A o 2 1 Outline ss CU DG GAD bf m 2 1 Calculate the Level Diameter Ratio L D Y LL I Fin 2 1 Identify Flow Unit Multiplier OND Suo EG SEN CO WNA FF 2 1 Square the Bins E P FR Fd ded WY ya CF RS 2 2 Caleulate the FIOW iU en yd Fd FN 2 2 Rectangular 6 ei onini Vo e DEUS 2 5 Rivers and Streams yR YA RS NO CD SG Fd 2 6 Blow UnitConversiOn sseni nnn Y gydd yn NN DA YL Dyw 2 7 SECTION III A PROFILING EXAMPLE USING THE MMI MODEL 2000 Collecting Field Data With The Model 2000 The 2 D 02000000 3 1 Field DAU p tov esie Ef ae 3 2 The 2 4 3 Method ngen adr dd 3 3 The IVES eM DNI 3 3 The Oe 25 max eo testi e datei etti gesti deer buc tase Be dapes dydy 3 3 The VPT Method nu a yn Y teat t mn t patti a rubet QU Nias 3 3 PP t EROR PRU ER 3 3 P OF DEVIATION tu tei udine mM YF id cd FSA 3 4 of Deviation Between High and Average eene enne nennen nne 3 4 of Deviation Between Low and Average 3 4 ii SECTION I PROFILING MEAN VELOCITY U DEFINITION A particle of water near the conduit wall will not move as fast as a particle toward the center To understa
19. cases this is usually located in the center just beneath the surface Multiply the fastest velocity by 0 9 for U 2 4 8 of Depth Method Measure depth of flow Page 1 5 Calculate the positions on the centerline by 0 2 x depth 0 4 x depth 0 8 x depth At the 2 4 and 8 positions measure and record the velocities Figure 1 2 Figure 1 2 2 4 8 Velocity Comment Positions In manmade channels measure the 2 4 and 8 positions from the bottom Average 2 and 8 velocities Average the 4 velocity with the 2 and 8 average for the U 1 3 4 Method A simplified version of the 2 4 8 method is to measure the velocity at the 4 position and use this as U This method is probably the least accurate because it uses only one data point and assumes that a logarithmic profile exists This is also called the 60 of depth method 2 D Method Locate the center line of the flow Locate vertical velocity lines VVL halfway between the center line and the side walls of the conduit This is measured at the widest part of the flow Take at least seven velocity measurements at different depths along the center line Take velocity readings at different depths on the VVL The distance between these depths should be the same as those on Figure 1 3 2 D Velocity the center line Positions Take final point velocity readings at the right and left corners of the flow Check the da
20. el 2000 The 2 D Method We start the 2 D profile on the vertical center line at the invert or bottom of the conduit The first velocity measurement with the Model 2000 is at 0 75 inches or 1 9 cm from the invert This is because the electrodes which measure the point velocity are 0 75 inches from the bottom of the sensor If the sensor is moved up 0 25 inches for the second velocity measurement this will put the electrodes one inch from the invert The sensor can then be moved at even inch or half inch incre ments Five to ten velocity measurements between the bottom and the surface are recommended After the vertical center line is profiled the level is measured and recorded Next the right and left vertical velocity lines are profiled and recorded Then the right and left corner velocity measurements are taken and recorded Finally the level is measured and recorded We now have the necessary data to calculate flow Comment If there is a sudden drop in velocity at any position check the sensor for debris 3 1 FIELD DATA CONDUIT DIAMETER 24 25 INCHES POSITION AS MEASURED CENTERLINE RIGHT VVL LEFT VVL FROM THE INVERT FT SEC FT SEC FT SEC 0 75 52 5 2 4 9 1 0 5 4 5 5 52 2 0 5 4 5 5 5 5 3 0 4 3 5 5 5 5 4 0 5 5 5 1 5 2 5 0 5 4 4 2 4 8 6 0 52 4 0 4 2 6 5 4 0 LEVEL DURING PROFILE 7 INCHES AVERAGE LEVEL RIGHT CORNER VEL LEFT CORNER VEL 6 INCHES 7 INCHES 4 0 FT SEC 4 8 FT SEC 7 is INCHES 7 has 6 e L E 5 BE
21. ence Reinitiate zero adjust start sequence Zero offset is greater than the zero adjust range Repeat the zero adjust procedure If the error is still displayed the unit needs servicing Conductivity lost or noise detected during zero adjust Usually caused by the sensor being out of the water KEY FUNCTION SUMMARY One Key Functions 24244 Turns Unit ON Clears the display and restarts the meter Turns Unit OFF Increments FPA TC and Memory Location Decrements FPA TC and Memory Location Alternates Between Recall and Real Time Operating Modes Stores Values In Memory Two Key Functions 742 224 Change Units Turns ON OFF Alternates Between FPA and 1C Filtering Clears Memory Initiates zero adjust sequence Zero stability is 0 05 ft sec 11 MAINTENANCE Routine maintenance of the unit is confined to cleaning the sensor and changing the batteries Cleaning the Sensor Nonconductive coatings oil and grease can cause noisy readings or conductivity lost errors Clean the sensor with soap and water If a problem still persists clean the electrodes with a very fine grit 600 sandpaper Do not use hydrocarbon solvents Changing Batteries A low battery flag is displayed when a low battery voltage is detected Check the battery change guide Page 13 for battery life estimates The battery compartment Figure 3 is located in the bottom of the meter To change the batteri
22. ero Adjust ret 9 MM T M NES 10 Error co M T a 10 Error 09 1 NM EE ES 11 Key Funcion Summary e aah ew ng ae dg cs deseo YF 11 One Key PUncHons occus i Ou adt fom Fa 11 TO t Ege uen seis ue GN Fd teat Y E UB aree 11 WIGEBIEN ANCE ee x eaten ein oscula C Ms cei cM tei cu eu Nuc tales 12 Cleamme the SensDE de ud AG 12 Chan mg Batteries ce ue ne e asc DD co Re ioc atop MN 12 lora eU EE PM E 13 Battery Change 13 Self Discharge in Storag 13 Low Battery M 13 Op Mon eO aeea e FY Co Ed GN O YN Ddw Ea dd GR fy 14 Sensor DISCONNECT un NL Cd ddyd O o Gy 14 Power In Signal Out Connector 14 Carrying asseu i T 15 SEIISOLS GA NOD voc O NA RATING NON RAA RUN ON ATO RIN MY O La 15 OneneChannelzX 15 Dull Pipe Velocity BetlSOE 16 Sensor Mounting Configurations icu ON atiis du ase c 16 Wniversal Sensor Mount eq ied taie i i 16 Standard Wading RO aac ea GG I7 Double Bnd Hanpern 17 Top Setting Wadin ROG Cusco recon e 18 OUspehsiomC able ss O A let e cutu
23. es unscrew the three captive screws on the bottom cover Remove cover and replace the batteries two D size Reinstall the bottom cover CAPTIVE Fl SCREWS d m ll E Td BATTERY COMPARTMENT Z 4 p Kd v LI 28 Figure 3 Battery Compartment 12 BATTERY LlFE The battery life will vary from unit to unit because of different battery types different ambient tempera tures and different applications The battery change guide below will help you to determine when to change the batteries until you gain experience in using your flowmeter in your application Battery Change Guide The hours shown in the battery life table are estimates based upon a continuous ON at an ambient temperature of 72 F 22 Battery Life Table BATTERY TYPE HOURS OF CONTINUOUS ON Alkaline 25 30 Carbon Zinc 5 Not Recommended NiCad 10 15 Per Charge Sanyo KR4400 D Typically the flowmeter is not continuously on and the ambient temperature varies from application to application The effect this will have on battery life is as follows Alkaline battery life will be increased by as much as 30 when cycled on and off At 32 F 0 C alkaline battery life will be reduced by 20 At 110 F 40 C alkaline battery life is increased by 10 Comment The power in signal out option is reguired for charging the NiCad batteries in the battery compartment See
24. hanging Flows A flow that is changing more than 1090 in three minutes or less can be classified as rapidly changing The 0 9 x Umax or 0 4 methods take the least amount of time However these methods usually reguire a typical profile shape for accurate results Comment Check the level several times during the profiling procedure If the level has changed but the change is less than 1090 average the level measurements and use the average in the flow calculation Asymmetrical flow The 2 D method is recommended for asymmetrical flows An asym metrical flow will have a difference of 30 or more between the right and left side velocities 1 2 Vertical drop outfalls The 2 D method is recommended for outfalls Remember to measure the level on the same plane as the velocity profile Outfalls should be avoided wherever possible Nontypical profile shape If you suspect a profile shape may not be typical use the 2 D method PROFILING CHECKS For best possible results you should Check the inside diameter of the conduit Also measure the horizontal and vertical diameters If there is a difference then average the diameters Check for symmetry of flow Check level several times during the procedure Check the invert for rocks sediment and other debris CALCULATING U PROFILING METHODS 0 9 x Umax Method Take a series of point velocity measurements throughout the entire flow Identify the fastest velocity In most
25. he d fi 9 T T d T ds channel into egual segments Figure 2 1 Then do a velocity profile and calculate the flow for each segment Sum the segment flows for the total flow The procedure for calculating flows in rivers and streams is as follows Figure 2 1 Segment Length Comment The smaller the segment the better the result If you find that the difference in mean velocity between two adjacent segments is greater than 10 the segments should be smaller Divide the channel width into segments of egual length d Figure 2 1 Locate the center line of each segment at i d Figure 2 2 Measure segment depth on the segment center line Comment The 2 6 and 8 positions for rivers and streams are measured from the surface All depth and velocity measurements must be on the same plane Calculate the 2 6 8 velocity positions on the segment centerline by 2 x Depth 6 x Depth Figure 2 2 Segment 8 x Depth Centerline Measure the velocity at the 2 6 and 8 positions Average the 2 and 8 velocities Average the 6 velocity with the average of the 2 and 8 velocities for Calculate segment areas Figure 2 4 Calculate the flow of each segment by Segment Area x Sum the flow of h segments for total flow Figure 2 3 Velocity Profile 2 6 RECTANGLE dxh A TRAPEZOID a b 2 xd A_ Figure 2 4 Segment Area Flow Unit Conversi
26. is only for circular conduits measured in feet The multiplier was derived using a one foot per second flow in a one foot diameter conduit as the model 2 1 Convert the Diameter to Feet and Sguare D Diameter in inches 12 Where D isin feet diameter squared The diameter needs to be converted to feet because the velocity is in feet per second Calculate the Flow K x D x U flow Example What is the flow in millions of gallons per day of a 10 inch diameter conduit with a 6 inch level The U has been calculated to be 1 5 ft sec Calculate Level Diameter Ratio L D Level ratio L D 6 inches 10 inches 0 6 Identify K K 0 6 0 3180 from Table I Calculate D D 10 in 12 0 833 ft 0 694 2 Calculate flow Kx D xU MGD 0 3180 x 0 694 ft x 1 5 ft sec 0 331 MGD Table I Flow Unit Multiplier K Flow Unit Mulitiplier L D MGD GPM CFS CMM CMD LPM 01 0009 5966 0013 0023 3 2522 2 2585 02 0024 1 6824 0037 0063 9 1709 6 3687 03 0044 3 0814 0069 0117 16 7986 11 6644 04 0068 4 7296 0105 0179 25 7811 17 9036 05 0095 6 5894 0147 0249 35 9190 24 9438 06 0124 8 6351 0192 0327 47 0701 32 6876 07 0156 10 8475 0242 0411 59 1295 41 0621 08 0190 13 2113 0294 0500 72 0148 50 0103 09 0226 15 7143 0350 0595 85 6585 59 4851 10 0264 18 3460 0409 0694 100 0039 69 4471 A1 0304 21 0975 0470 0799 115 0022 79 8627 12 0345 23 9609 0534 0907 130 6108 90 7020 13
27. les with the universal sensor mount Figure 9 Mounting instructions are as follows UR Profiling Insert the mounting shaft on the universal t go Adapter mount into the hole at the back of the sensor The thumbscrew needs to be seated in the A En groove so make sure the shaft is completely Ci ii inserted into the hole Hand tighten the thumbscrew Sensor Slide a pole one inch or less in diameter through the clamp and tighten Figure 9 Universal Sensor Mount CAUTION Do not over tighten the thumbscrew on the sensor Excessive force on the thumbscrew could damage the sensor 16 7 Standard Wading Rod Intermediate Section Both the metric and English standard wading rods have a base bottom section double end hanger and three intermediate sections Figure 10 Each intermediate section is two feet in length English or one half meter in length metric The bottom section is shorter but when it is screwed to the base the overall length is egual to the intermediate sections Each section is divided into 0 10 foot single marks 0 50 foot double marks and 1 0 foot triple marks increments English or 5 cm single marks and 10 cm double marks increments metric Base Section e Base ep 7 MOUNTING NE ML 24 P i yd E an ym F UE N J 4 A N NES itr Figure 10 Standard Wading Rod Figure 11 DaublesPud Hanger
28. nd this we need to look at the molecules of moving liguids The first layer of molecules stick to the wall of the conduit The next layer will move by sliding across the first layer This happens throughout the flow with each successive layer moving at a faster velocity The change in velocity is greater near the conduit wall than it is toward the center If velocity measurements of each layer could be taken a velocity profile similar to the one in Figure 1 1 would be produced Notice that the velocity decreases near the surface Since most flows fit this profile this is called the typical profile There are however situations which will cause other profile shapes and it is usually more difficult to calculate flow with these shapes To calculate flow an average or mean of all the varying velocities must be determined Since it is not practical to measure the velocity of each layer of molecules methods have been developed by which a mean velocity U can be determined from velocity measurements taken at a number of positions in the flow VELOCITY Figure 1 1 Typical Profile CROSS SECTIONAL AREA The cross sectional area of the flow is determined from a level measurement and the channel shape It is important that the mean velocity measurement and the level measurement is done at the same location in the channel 1 1 SITE SELECTION A site that produces the typical profile shape will give the most accurate results In a majority
29. of the cases problem sites can be identified by a visual inspection Site inspection guidelines are as fol lows The channel should have as much straight run as possible Where the length of straight run is limited the length upstream from the profile should be twice the downstream length The channel should be free of flow disturbances Look for protruding pipe joints sudden changes in diameter contributing sidestreams outgoing sidestreams or obstructions Clean any rocks sediment or other debris that might be on the bottom of the pipe The flow should be free of swirls eddies vortices backward flow or dead zones Avoid areas that have visible swirls on the surface Avoid areas immediately downstream from sharp bends or obstructions Avoid converging or diverging flow approach to a flume and vertical drops Avoid areas immediately downstream from a sluice gate or where the channel empties into a body of stationary water Choosing the Method profiling methods can be used in a site that produces a typical profile and has sufficient level to measure three point velocities If you cannot avoid sites with nontypical profiles or low flows the following guidelines will help in choosing a method that will give the best results Keep in mind that choosing the method will become easier as you gain experience in profiling Low flows The 0 9 x Umax method is recommended in flows of less than two inches Rapidly C
30. on To convert flow units locate the appropriate flow unit conversion factor in Table III Then multiply the existing unit s conversion factor to get the new unit s Table HI Flow Unit Conversion Factors NEW UNITS CFS MGD GPM CMD CMM E 1 0 64632 448 831 2446 576 1 69901 1 1 54723 1 694 44 3785 412 2 62876 0 002228 0 00144 1 5 45099 0 0037854 N 0 000408 0 0002642 0 18345 1 0 0006944 x 0 5885 0 380408 264 172 1440 1 Example Convert 20 ft sec CFS to millions of gallons per day Solution From Table III conversion factor 0 64632 Then 20 ft sec x 0 64632 12 9264 MGD Table IV Flow Units CMM Cubic Meters per Minute CMD Cubic Meters per Day LPM Liters per Minute MGD Millions of Gallons per Day GPM Gallons per Minute CFS Cubic Feet per Second 2 7 SECTION A PROFILING EXAMPLE USING THE MMI MODEL 2000 This section illustrates how to collect and analyze data from circular conduits and achieve the best possible accuracy The data shown in this section is actual field data that was collected with a MMI Model 2000 in a normal flow Comment A 2 D profile is used to collect the field data since this method provides the most point velocity measurements A centerline profile is plotted and a best fit curve is drawn This permits all profiling methods described in Section I to be utilized with one set of velocity measurements Collecting Field Data With the Mod
31. onics at the factory Display segment test The unit will light all display segments Velocity output The first few readings are not filtered however they are accurate Ala A AM A amp Secus VERSION HES PLAY LOW SEC aM NOISE 1 H H H FT S Wr FN COH LOST Fm E a M S T DISPLAY PERICO i mt VELOCITY OUTPUT DISPLAY Units of Measurement Beeper The Model 2000 can output velocity in ft s or m s When the beeper symbol is shown the beeper is active Press down on the ON C and OFF keys simultaneously to cycle between FT S no beeper 5 no beeper F S with beeper Baaper M S with beeper Shom when the keeper mh is active Fixed Point Average Time Constant Filtering The fluid dynamics around the sensor electrodes may cause the readings to bounce around To stabi lize the readings the output to the display is dampened The display can be dampened by Fixed Point Averaging FPA or by time constant filtering rC Fixed Point Averaging is an average of velocities over a fixed period of time Time constant filtering is a software algorithm that mimics an RC analog circuit Press the 7 and 4 keys simultaneously to alternate between the FPA and rC displays FPA The display will show the letters FPA when you first switch to the FPA display Except for the first period the display is updated at the end of each averaging period For example
32. ple this would be 5 4 feet Line up the 5 on the foot scale with 4 on the tenth scale To set the sensor at 80 of the depth divide the total depth by two and repeat the above procedure In the above example this would be 1 35 feet Line the 1 on the foot scale with 0 35 on the tenth scale 18 0 7 FT TENTH SCALE 2 ENGLISH CM SCALE METRIC SLIBING ROD FT SCALE EMGLISH x10 SCALE METAK Figure 12 Top Setting Wading Rod 19 Suspension Cable The suspension cable Figure 13 makes it possible for the sensor to be lowered into the water from boats or bridges To attach the sensor to the suspension cable insert the mounting shaft on the sensor mount into the hole at the back of the sensor The thumbscrew needs to be seated in the groove on the shaft so make sure the shaft is completely inserted into the hole Hand tighten the thumbscrew WEIGHT HANCGER n H TU PAN 42033 Sr e k Fi c i WEIGHT a bh SENSOR oe ue F a a Ps s rj D d Figure 13 Suspension Cable 20 OPEN CHANNEL PROFILING HANDBOOK JANUARY 1989 REV 1 MAY 1990 REV 2 JANUARY 1994 Marsh McBirney Inc 4539 Metropolitan Court Frederick Maryland 21704 9452 www marsh mcbirney com 301 874 5599 800 368 2723 FAX 301 874 2172 P N105 0030 01 REV2 OPEN CHANNEL PROFILING SCOPE This handbook contains the inst
33. ption of the first empty location only the locations that have stored readings can berecalled The period bar will stationary while the unit is in the recall moda EN z M S pep CO To clear memory press the ON C and STO keys simultaneously Memory can be cleared from both the the Recall and Real Time operating modes ZERO ADJUST Zero Check First clean the sensor Page 12 because a thin film of oil on the electrodes can cause noisy readings Then place the sensor in a five gallon plastic bucket of water Keep it at least three inches away from the sides and bottom of the bucket To make sure the water is not moving wait 10 or 15 minutes after you have positioned the sensor before taking any zero readings Use a filter value of 5 seconds Zero stability is 0 05 ft sec Zero Adjust Position the sensor as described in the zero check procedure To initiate the zero start seguence press the STO and RCL keys at the same time You will see the number 3 on the display Decrement to zero with the key gt Mb 44 4 amp 3 The unit will decrement itself to zero and turn off The unit is now zeroed The number 32 will be displayed Comment Each key in the zero adjust seguence must be pressed within 5 seconds of the previous key If the time between key entries is longer than 5 seconds or if a wrong key is pressed the unit will display an ERR 3 Turn the unit OFF then back
34. red by two D size batteries in the bottom of the case A shoulder strap and 20 feet of sensor cable are standard Excess sensor cable is coiled and secured to the shoulder strap by the sensor cable re tainer Figure 1 Model 2000 Flo Mate THEORY OF OPERATION The Flo Mate measures flow using the Faraday law of electromagnetic induction This law states that as a conductor moves through a magnetic field a voltage is produced The magnitude of this voltage is directly proportional to the velocity at which the conductor moves through the magnetic field When the flow approaches the sensor from directly in front then the direction of the flow the mag netic field and the sensed voltage are mutually perpendicular to each other Hence the voltage output will represent the velocity of the flow at the electrodes The sensor is eguipped with an electromagnetic coil that produces the magnetic field A pair of carbon electrodes measure the voltage produced by the velocity of the conductor which in this case is the flowing liguid The measured voltage is processed by the electronics and output as a linear measure mentof velocity VOLTAGE VECTOR fr v a ff PAN ee f V aN h h 7 We ANN LA G EM LU Y TAS a Vi in A E V j 5 MAGNETIC FIELD Figure 2 Theory of Operation DESIGN FEATURES The Model 2000 design features are
35. ructions on how to measure the velocity profile and calculate the flow of open channels The velocity profile is measured using a handheld velocity meter Flow is calculated with the continuity equation O Ux A where O is flow U is mean velocity and is cross sectional area Section I describes mean velocity cross sectional area site selection profiling and methods of determining the mean velocity Section II describes methods of calculating the instantaneous flow rate Section III is a case study with the MMI Model 2000 being used to determine U CONTENTS SECTION I PROFILING Mean Velocity U Definition os Cd ra er GN a CS 1 1 Cross Sectional ATCA QR S RE OG GA Fd YU Oath tute Fd NN FON HONG SG GYS 1 1 Site DELS CH ON YN 1 2 Choosmehe Method cc fests A a y 1 2 Profiline Checks Rc n 1 3 f acest _ cc A Y aA cL Un 1 3 0 9 x Vmax Method 1 3 2 4 OW Depth Mead se ue dot yn 1 3 A Methods e Od Fn gd SA tabs Ye E 1 4 2 bd au TE 1 4 2 1 Nethod METALS seii Pos ab eoe VI eo Ed Wyd Fd dwyd 1 4 Ed Wis Chod i 1 5 Measunna Level eno GG O Cd Eg gd Ry bo GU GO fT edd SF 1 5 S eoi eu tut oc o ml GW 1 5 SECTION II CALCULATING FLOW Circul
36. s M 20 ii Velocity Measurement Method Electromagnetic Zero Stability 0 05 ft sec Accuracy 2 of reading zero stability Range 0 5 to 19 99 ft sec 0 15 m sec to 6 m sec Power Requirements Batteries Two D Cells Battery Life Continuous ON hours Alkaline 25 30 NiCad 10 15 per charge External Power Supply Optional 120 1 Wor 220 V 1 W Water Resistant Electronic Case Submersible One Foot for 30 Seconds SPECIFICATIONS Outputs Display 312 Digit Signal Output Connector Optional Analog 0 1 V 1 ft sec or 1 m sec 2 V Full Scale Materials Sensor Polyurethane Cable Polyurethane jacket Electronic Case High Impact Molded Plastic Weight 3 lb 9 oz with case and 20 ft of cable 2 lb 10 oz without sensor and cable Temperature Open Channel Velocity Sensor 32 F to 160 F 0 C to 72 C Full Pipe Sensor S S Insertion Tube 32 F to 160 F 0 C to 72 C 250 psi Electronics 32 F to 122 F 0 C to 50 C iii GENERAL DESCRIPTION The Marsh McBirney Model 2000 Flo Mate is a portable flowmeter designed for use in both the field and the laboratory The unit uses an electromagnetic sensor to measure the velocity in a conductive liguid such as water The velocity is in one direction and displayed on a digital display as feet per second ft s or meters per second m s A watertight case protects the electronics from wet weather and accidential submersions The unit is powe
37. ta for any outliers If a best fit curve of the velocity profile were plotted an outlier would lie outside the best fit curve region See Figure 3 1 on Page 3 2 Average all measurements except outliers for U Remember to include the corner measurements 2 D Method Alternate Another way to do the 2 D profile is with the FPA fixed point average feature of the Model 2000 Flo Mate The Flo Mate sensor is moved at a constant velocity in a pattern across the flow that covers the cross sectional area The velocity displayed by the Flo Mate at the end of the FPA period is the mean velocity FINISH Comment It may take several attempts to get the FPA time set so that the end of the FPA period coincides with the end of the sensor motion Set the FPA time to the appropriate number of seconds Place the sensor at the start position and wait for a few sec Figure 1 4 2 D Method onds Alternate Press lt ON C gt and start moving the sensor 1 4 VPT Method The Velocity Profiling Technigue VPT was first described by N T Debevoise and R B Fernandez in the November 1984 issue of the WPCF Journal With this method a series of point velocity measurements are taken at different depths along the centerline of the flow These measure ments along with level are input into a VPT computer program which calculates the flow This is one example of the more advanced profile integration technigues which are possible MEASURING
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