West Systems Portable diffuse flux meter Handbook Download Page 89

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11 WS-VOC Volatile Organic Compounds detector

EST

Syst

PAG

tsy

stems

.co

EST

Syst

Once connected, the app shows all the

available sensors.
Tap on the VOC detector to start the

calibration.

Warning: as soon so the calibration

starts, the calibration parameters stored

in the VOC detector will be reset to fabric
default.

By clicking continue, the previous
calibration data will be overwritten.

Continue only if you have everything that
is needed for completing the calibration

(the zero and span mixtures).

Summary of Contents for Portable diffuse flux meter

Page 1: ...Portable diffuse flux meter Release 9 1 January 2019...

Page 2: ...WEST Systems WEST Systems...

Page 3: ...writing to support westsystems com and providing information about part number serial number and description of the issue Instructions on packaging and shipping will be e mailed back to the Customer...

Page 4: ...y costs custom problems etc Check that the Company your shipping agent chooses lands in Galileo Galilei Airport in Pisa If not ask your shipping agent to change the Company or send the items by DHL or...

Page 5: ...e measurement 28 4 3 Quantifying the flux 32 Components 37 5 1 Accumulation chamber 37 5 2 Pump 42 5 3 Fluxmeter battery 44 5 4 Fluxmeter battery charger 45 5 5 Backpack 47 5 6 Tubes 47 5 7 Filters 49...

Page 6: ...C Volatile Organic Compounds detector 83 11 1 Specifications 84 11 2 Measuring principle 85 11 3 Warm up 85 11 4 VOC fluxes measurement 85 11 5 Calibration check 86 11 6 Calibration 88 11 7 VOC correc...

Page 7: ...Hydrogen Sulfide is a poisonous gas air concentration higher than a few ppm can be lethal the short term exposure limit STEL recommended by NIOSH is 10 ppm Diffuse carbon dioxide fluxes are normally...

Page 8: ...vity perform a full charge of the batteries at least every 3 months 2 3 Filters and tubes Connect the chamber to the fluxmeter using the provided black blue twin tubes In some cases the colour of the...

Page 9: ...rument will turn off automatically after one hour if not under the control of FluxManager software Once powered the fluxmeter runs the initialization process which takes about 20 seconds During the in...

Page 10: ...re and in case the value is below 50 C it will ask the user if he wish to continue The user can continue being aware of the previous considerations Normally the sensor after a cold startup requires ab...

Page 11: ...device comes from West Systems with the app pre installed In case you acquired the mobile device separately install the app by opening Google Play Store from the device and looking for Fluxmanager2 C...

Page 12: ...3 FluxManager Software WEST Systems PAGE 12 www westsystems com WEST Systems...

Page 13: ...scan operation is completed you can repeat it by pressing the Scan button On the contrary if all the expected instruments are on the list the user can proceed with pressing the Connect button It is n...

Page 14: ...remains active for all the sensors regardless of whether or not the sensor is in fogeround or background or has the track disabled Initially only current reading and the elapsed time are displayed Tou...

Page 15: ...ove the left and right cursors to the desired position To move the cursors you have to touch the screen close to the limit you want to move and drag it to the correct position The software will move t...

Page 16: ...ing time Once the sampling is completed press the Stop button to end the acquisition The chamber and the pump will continue to run for a number of seconds usually 30 seconds but it can be overwritten...

Page 17: ...site name Note the name of the site is used to display the recorded points on the map Only the points related to the most recent site name will be displayed Hence changing the name of the site in the...

Page 18: ...the field is automatically filled with the value recorded by the probe average value of the 1 Hz sampling during the measurement If this value is not available or if the user prefers to use its own se...

Page 19: ...emote locations The most common locations where to save the backup copy are 3 SD card In this case the data is still lost in case of loss or theft of the smartphone but is safe in case of damage of th...

Page 20: ...he cable is plugged you should be able to select on the device the MTP mode Once the smartphone is connected open the file explorer on the PC and navigate inside the Android device internal memory You...

Page 21: ...oogle Map servers For this reason the visualization is active only if the Android device has an Internet connection available Moreover the Google Play Services component must be updated on the Android...

Page 22: ...r each sensor This setting affects only the on field visualization the sensor with chart disabled are sampled and recorded in the same way as the others one reading per second The entire recording is...

Page 23: ...ssing By placing the left and right cursors on the chart the app shows the value of the linear regression within the selected interval and the related R2 coefficient The regression line is also drawn...

Page 24: ...mber fan remain ON in order to clean the fluxmeter tubes and sensors cell with atmospheric air During the cleaning time the chamber must be raised from the soil Usually 20 30 seconds are enough for cl...

Page 25: ...software WEST Systems PAGE 25 25 www westsystems com WEST Systems WEST Systems The menu About show the firmware and software version of the connected devices Please provide this information when reque...

Page 26: ...t and the FluxManager software To better understand the this chapter a basic theory is explained The theorical flux curve is shown in the figure below The plot represent the variation of the concentra...

Page 27: ...ore than 5 The two vertical lines delimit the interval where to compute the flux To have a good evaluation of the flux the correct interval of the flux curve has to be selected Never compute the flux...

Page 28: ...ccount of the accumulation chamber shape and of the environmental parameters to transform the slope into a flux evaluation This matter is described in detail in the chapter 4 The complete theory of th...

Page 29: ...mulation shapes The perfect curve The shape of the curve is quite perfect and the computation of the flux is done with a very good accuracy R2 regression quality factor very close to 1 Air contaminati...

Page 30: ...measure in air one meter above the soil surface and afterwards repeat the flux measurement You can use the measurement choosing the second part of the curve for regression computation Selecting the s...

Page 31: ...s no flux 14 The pump is not working 15 The tubes are not connected correctly Very high flux The first part of the curve is not linear The problem is due to the combined effect of the high flux and th...

Page 32: ...trument measures the barometric pressure and the air temperature inside the chamber Choosing the flux measurement unit The first measurements made 20 years ago with the accumulation chamber was expres...

Page 33: ...ation chamber factor in the A c K field This operation can be critical In any case on the saved files you ll find the results of flux evaluation expressed in both units the raw ppm sec and the moles s...

Page 34: ...4 Measuring flux WEST Systems PAGE 34 www westsystems com WEST Systems Accumulation chamber A factors Volume 0 00277 m3 Area 0 0308 m2...

Page 35: ...4 Measuring flux WEST Systems WEST Systems PAGE 35 35 www westsystems com WEST Systems Accumulation chamber B factors Volume 0 006186 m3 Area 0 0317 m2...

Page 36: ...4 Measuring flux WEST Systems PAGE 36 www westsystems com WEST Systems Accumulation chamber C factors Volume 0 006878 m3 Area 0 0712 m2...

Page 37: ...ase area 0 0308 m2 Internal height 98 mm Mass 1 35 Kg with battery Net volume 0 006186 m3 Base area 0 0317 m2 Internal height 198 mm Mass 1 55 Kg with battery Net volume 0 006878 m3 Base area 0 0712 m...

Page 38: ...ve demonstrated that if soil is disturbed for example levelling the ground or digging a hole in order to place the chamber the flux condition varies in an unpredictable way and takes a long time to st...

Page 39: ...minal voltage 8 4 V Max charge voltage 10 5 V In case of emergency for example if you are out in the field with low battery and no possibility to recharge the internal battery can be replaced by a com...

Page 40: ...The sensor is placed inside the chamber on the ceiling The sensor is NOT protected against water or accidental impacts Please be careful when placing the chamber on the ground Pressure sensor The bar...

Page 41: ...hamber and the surrounding air outside the chamber avoiding the pressurization of the chamber that would alter the gas flow from the soil Make sure it is not obstructed by dust clean it if necessary S...

Page 42: ...50 mA 12 Volts Manufacturer KNF Order model NMP 830 KNDC Pneumatic fittings diameter 4 mm In order to avoid unwanted variation of pumping flow due to power supply the pump is supplied with a stabilize...

Page 43: ...5 Components WEST Systems WEST Systems PAGE 43 43 www westsystems com WEST Systems 21 Reassemble the head...

Page 44: ...tee operation during a whole working day To replace the battery unplug the battery connector from fluxmeter internal panel and remove the knob as indicated in the picture Charge the battery after each...

Page 45: ...use please think about disconnecting the charger from the mains This will reduce the risk of hazards reduce the products environmental impact and save electricity costs The charger must be kept away f...

Page 46: ...manufacturers recommend that trickle charge does not exceed 24 hours If in doubt contact the battery manufacturer for details If the safety timer runs out before dV is detected the charger will go di...

Page 47: ...Manufacturer SMC Order code RS 686 2680 Chamber twin tube for connecting the chamber to the fluxmeter Internal diameter 4 mm External diameter 6 mm Material Polyurethan Color Black Blue or White Blue...

Page 48: ...5 Components WEST Systems PAGE 48 www westsystems com WEST Systems Fluxmeter inlet port Fluxmeter outlet port PTFE membrane filter 50 mm...

Page 49: ...rofibre filter cartridge filter Filtration efficiency 93 at 0 01 m Order code Balston 9922 05 DQ The PTFE membrane filters are permeable to gases and water vapour and are impermeable to liquid water a...

Page 50: ...er calibration For fluxes between 300 and 700 moles m2 day the injected flux is controlled by means of a mechanical flow reducer and measured using a bubble flowmeter Accuracy 3 before and after the f...

Page 51: ...ement error versus the imposed flux of carbon dioxide expressed in grams per square meter per day at different pumping flow rates In order to avoid unwanted variation of pumping flow due to power supp...

Page 52: ...g device rotation speed The following plot shows the measured flux vs the mixing device rotation speed Battery status vs RPM The following plot shows the mixing device RPM Rotation per minute vs power...

Page 53: ...ger files The selected folder will be proposed the next time you start the software Select the folder and press OK If there are valid files the application will start to parse the data To estimate the...

Page 54: ...of chamber e g A B C that you inserted in the FluxManager software Check that the information about the chamber type A in the illustration is correct the displayed type is the one obtained from the f...

Page 55: ...mperature in the measures that are missing this parameter replace the default values 1013 mBar and 20 C and press OK If the Apply to all analysis box is checked the parameters in the measures that alr...

Page 56: ...com WEST Systems WEST Systems Selecting an item in the list or pressing one of the navigate buttons the flux curves are displayed Like in FluxManager are displayed the graphs of the sensors with TRAC...

Page 57: ...lt of the regression computed on the field Moving the regression left and right limit will cause the immediate update of the fields Graph Displays the concentration vs time plot The red points are use...

Page 58: ...existing interval will be overwritten We recommend saving the original FluxManager files in a folder and working with FluxRevision on a copy of the data 7 1 Report file The report file is a table wher...

Page 59: ...TAB character so the file can be easily opened with a spreadsheet editor e g Microsoft Excel The LONGITUDE and LATITUDE fields are populated with the original data collected by the smartphone integra...

Page 60: ...he FluxManager app as explained on chapter 3 Obviously it is important that the injected mixture does not contain carbon dioxide The method for injecting standard gas mixtures is explained in detail i...

Page 61: ...ar bag or equivalent for the zero mixture and one for the span mixture We suggest to label them in order not to switch them Calibration Preliminary operations install the LI COR application on the lap...

Page 62: ...Set the sampling frequency to 1 Hz The application shows the current concentration reading as well as the cell temperature and pressure Note the heater must be ON 8 Check the temperature of the cell...

Page 63: ...ect the bag at the inlet port of the fluxmeter The CO2 concentration should rise 13 Fill the Span gas concentration ppm field with the actual CO2 concentration of your mixture e g if the CO2 content i...

Page 64: ...llows increasing the pathlength in the gas The IN and OUT gas fittings can be used with rilsan 6x4 mm tubes or silicon 5x3 2 tubes Please respect inlet and outlet ports Always make sure that a filter...

Page 65: ...0 C 45 C Selectivity to methane Flux Measurement range from 1 to 900 000 millimoles m2 per day Range Unit Precision 0 1000 mmoles m per day 25 1000 150 000 mmoles m per day 10 150 000 900 000 mmoles m...

Page 66: ...westsystems com WEST Systems The following plot ppm vs seconds shows a stability test while injecting atmospheric air for about 1 000 seconds The plot ppm vs seconds shows an accumulation curve while...

Page 67: ...nsor needs to apply different settings on the laser diode This adaptations produce a gap of a few seconds during which a valid concentration value is not available 9 2 Computing flux The sensor presen...

Page 68: ...you cross that threshold during the accumulation curve please apply the interpolation on the second part of the curve Do not include the ten seconds gap into the linear regression in order to prevent...

Page 69: ...nto the detector we suggest filling a gas sampling bag e g Tedlar bag from the cylinder and then let the pump of the fluxmeter flow the gas inside the detectors In this way it s possible to recreate a...

Page 70: ...e 30 C to 50 C Air pressure 800 hPa to 1200 hPa Air RH 15 90 non condensing Expected sensor life 24 months Chemical cell order code WEST H2S BH Detector order code WEST TOX 05 H2S BH Factory calibrati...

Page 71: ...these cross sensitivity are reported Test ppm Reading ppm SO2 Sulfur Dioxide 20 2 NO Nytrogen monoxide 50 1 5 NO2 Nytrogen dioxide 10 3 Cl2 Chlorine 10 2 5 H2 Hydrogen 400 1 C2H4 Ethylene 400 0 4 CO...

Page 72: ...ion check fails error 5 it is recommended to calibrate the detector Follow the procedure below 1 Switch on the fluxmeter and start a measurement with FluxManager in order to get the pump flowing 2 Let...

Page 73: ...on the H2S detector to start the calibration 6 Warning as soon so the calibration starts the calibration parameters stored in the H2S detector will be reset to fabric default By clicking continue the...

Page 74: ...s finally stable select the interval by tapping on the screen The average and standard deviation of the selected period is shown on the display A lower standard deviation indicates a good signal stabi...

Page 75: ...f the span gas mixtures is 25 ppm 11 When the signal is finally stable select the interval by tapping on the screen The average and standard deviation of the selected period is shown on the display A...

Page 76: ...l screen the app shows the average values that were selected for the zero and span gas mixtures Input the H2S concentration in ppm of the span calibration mixures 25 in the example Press the CALIBRATE...

Page 77: ...10 WS TOX H2S Hydrogen sulfide detector PAGE 77 www westsystems com WEST Systems WEST Systems 10 2 Replacing the sensor head...

Page 78: ...ST Systems WEST Systems WEST Systems Now install the new sensor head WS H2S BH Head and re assemble the detector Please check the O Ring status and check the sealing of the sensor head on line adapter...

Page 79: ...is electronically stabilized Accuracy 3 For fluxes between 0 06 moles m2 day and 0 6 moles m2 day the injected flux is controlled by means of a mechanical flow reducer and measured using a bubble flo...

Page 80: ...sing the accumulation chamber B that s more accurate for the hydrogen sulfide measurement Room temperature Between 20 2 and 21 4 C Air relative humidity 52 54 Barometric pressure between 1013 1 and 10...

Page 81: ...cal hydrogen sulfide flux curve the slope is 0 028 ppm sec and the flux is 0 019 moles sm day In the plot below the base line of the hydrogen sulfide detector output is reported The initial drift is d...

Page 82: ...ector PAGE 82 www westsystems com WEST Systems WEST Systems WEST Systems In the plot below the stability of the hydrogen sulfide detector output is reported The injected gas mixture at 1 liter per min...

Page 83: ...communication lines to the sensor The cable pinout is shown in the following table Pin Signal 1 Gnd Legend 2 Gnd Gnd Ground reference for power supply and RS485 3 VDC VDC 10 28 Volts Power supply inp...

Page 84: ...nge from 40 to 55 C Temperature relative humidity and pressure sensors are installed inside the measurement cell The sensitive element is installed in contact with the gas sample Temperature Measureme...

Page 85: ...started 1 Switch on the fluxmeter Wait for the initialization to complete 2 Start the FluxManager app connect and press the Start button In this way the pump is turned on and start flowing atmospheric...

Page 86: ...rrect functioning of the chamber and to assess the correct accumulation In almost any type of soil it is possible to detect a CO2 flux If the CO2 curve does not show a linear or exponential increment...

Page 87: ...een as explained on chapter 3 Obviously it is important that the injected mixture does not contain traces of VOC Step 2 Verification of the span Fill the second Tedlar bag with a standard mixture cont...

Page 88: ...n If the calibration check has returned a negative outcome error 5 it is recommended to recalibrate the sensor Apply the following procedure 1 Switch on the fluxmeter and start a measurement with Flux...

Page 89: ...ap on the VOC detector to start the calibration 6 Warning as soon so the calibration starts the calibration parameters stored in the VOC detector will be reset to fabric default By clicking continue t...

Page 90: ...l is finally stable select the interval by tapping on the screen The average and standard deviation of the selected period is shown on the display A lower standard deviation indicates a good signal st...

Page 91: ...ation of the span gas mixtures is 25 ppm 11 When the signal is finally stable select the interval by tapping on the screen The average and standard deviation of the selected period is shown on the dis...

Page 92: ...final screen the app shows the average values that were selected for the zero and span gas mixtures Input the concentration in ppm of the span calibration mixtures 25 in the example Press the CALIBRA...

Page 93: ...onse factor RF expresses the ratio between the PID response to the particular compound and the PID response to the calibration gas isobutylene If the RF is 1 the PID response to a certain concentratio...

Page 94: ...propane 1 10 04 2 Bromo 2 chloroethane 1 10 57 3 Bromo 2 methylpentane 1 10 09 2 Bromoacetone 9 73 1 Chemical name IE eV RF Bromoacetylene 10 31 4 Bromobenzene 8 98 0 32 Bromobutane 1 10 13 1 6 Bromob...

Page 95: ...1 Citronellol acetate 9 1 5 Citronellol formate 9 1 5 Citronellyl isobutyrate 9 0 9 Coumarin 9 0 4 Creosote 9 1 Cresol m 8 36 2 2 Chemical name IE eV RF Cresol o 8 14 1 1 Cresol p 8 31 1 1 Cresyl ace...

Page 96: ...rbonate 10 52 60 Dimethyl disulfide 8 46 0 2 Dimethyl ether 10 03 1 3 Dimethyl phosphite 10 53 8 Dimethyl phthalate 9 64 1 Dimethyl sulfoxide 9 10 20 Chemical name IE eV RF Dimethylacetamide N N 8 81...

Page 97: ...Eugenol 9 0 4 Eugenol methyl ether 9 0 4 Fenchol 9 0 4 Ferrocene 6 88 0 8 Fluorobenzene 9 2 0 74 Fluorobenzoic acid 4 9 91 2 Formamide 10 20 2 Furan 8 88 0 4 Furfural 9 21 0 8 Furfuryl alcohol 9 9 2...

Page 98: ...Fuel Jp 8 9 0 7 Kerosene 8 0 8 Ketene 9 62 3 Chemical name IE eV RF Linalool oxide 9 0 6 Linalyl acetate 9 1 1 Maleic anhydride 9 9 2 Mandelic acid 0 8 Menthol 9 0 5 Menthone 9 0 4 Mercaptoacetic acid...

Page 99: ...pentyl alcohol 9 72 2 Nitric oxide 9 27 8 Nitroaniline 4 8 56 0 8 Nitrobenzene 9 92 1 7 Nitrogen trichloride 10 1 1 Nitrogen dioxide 9 58 10 N Methylolacrylamide 10 3 2 Nonane 9 72 1 4 Nonanol mixed i...

Page 100: ...ert butyl bromide 9 92 0 99 Chemical name IE eV RF Tert butyl formate 10 52 8 Tetrabromoethane 1 1 2 2 10 2 Tetracarbonylnickel 8 28 1 Tetrachloroethylene 9 33 0 4 Tetrachloronaphthalene 1 2 3 4 1 Tet...

Page 101: ...ne 9 9 1 Trioxane 10 3 2 Turpentine 8 5 0 6 Turpentine oil 8 0 6 TVOC 10 1 Undecane 9 56 1 1 Vanillin 9 1 Vinyl acetate 9 19 1 5 Vinyl bromide 9 8 1 5 Vinyl chloride 9 99 2 1 Vinyl ethyl ether 8 98 1...

Page 102: ...oni M Guidi B Raco and L Marini Appl Geochem 13 543 552 1998 Diffuse CO2 efflux from Iwojima volcano Izu Ogasawara arc Japan Notsu K Sugiyama K Hosoe M Uemura A Shimoike Y Tsunomori F Sumino H Yamamot...

Page 103: ...ence on Waste Management and the Environment 469 478 2002 Precursory diffuse carbon dioxide degassing related to a 5 1 magnitude earthquake in El Salvador Central America J M L Salazar N M P rez P A H...

Page 104: ...04 www westsystems com Soil CO 2 and Temperature Monitoring Station Handbook Release 00 November 2011 WEST Systems WEST Systems www westsystems com Portable soil flux meter handbook Release 9 1 Januar...

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West Systems Portable diffuse flux meter, Handbook, Page: 89 / 104

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