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Dynamax HPFM3 Installation And Operation Manual Download Page 74

Revision: JUNE 2017

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Summary of Contents for HPFM3

Page 1: ... Meter Installation and Operations Manual 10808 Fallstone Rd Suite 350 Houston TX 77099 USA Toll Free 1 800 896 7108 Phone 281 564 5100 FAX 281 564 5200 E mail admin dynamax com International Email exports dynamax com Website www dynamax com ...

Page 2: ...Adding Degassed Water to the HPFM 30 5 4 1 Making Degassed Water Preventing Algae Buildup Inside the HPFM 31 5 4 2 Priming a Totally Empty Captive Air Tank CAT 32 33 5 4 3 Adding water to a Partly Empty Captive Air Tank CAT 33 34 5 5 EliminationAirfromtheHPFM 34 35 5 5 1 Purging Air from the Water Filter 35 36 5 5 2 Removing Air Trapped in the 8 way Manifold 36 5 5 3 Removing Microscopic Air Bubbl...

Page 3: ...stributed in the wood of a large branch 58 8 3 Cautions when measuring small flows conductance or larger resistances 58 8 4 Air Bubbles 59 61 9 0 Connecting the HPFM to the Roots and Shoots 62 67 10 Disconnecting the HPFM 68 10 1 Valve Settings for moving the HPFM 68 10 2 Disconnecting and Moving the HPFM 68 11 Maintaining the HPFM 69 11 1 Changing the Water Filter 69 12 Calibration of the HPFM 70...

Page 4: ...t is completed in as little as 10 minutes HPFM Gen3 measures the major components of the hydraulic conductance in the soil plant atmosphere continuum reference 70 The hydraulic architecture of a whole shoot or of a single leaf can be represented by a resistance diagram similar to the electronic circuit shown One can measure the values of the individual hydraulic resistances then compute the patter...

Page 5: ... more resolution with a highly advanced analog processing board 24 bit A D Highest analog resolution on the market provided USB powered Analog to digital circuit Batteries not required Single USB high speed data stream No more parallel port to add Powerful instant regressions with chart saving and printing All regression and streaming data are saved automatically No more hand written data Individu...

Page 6: ...tance Conductance new Flow new Ten Point Average Option Large easy to read pressure gauges are digitally painted on screen Color coded ranges automatically defined Audible and graphic warnings provided to prevent over pressure or out of range readings Flow gauge readout in of full scale as well as a detailed 2D chart in Kg s 1 Easy to read raw data display of all important parameters Set up and co...

Page 7: ...ure in A never exceeds 0 6 MPa and the air supply is 4 2 MPa 609 PSI the pressure drop across the NV is approximately constant This allows the rate of pressurization in the water to be approximately linear with time Pressurized water flows from the CAT to the 8 Way Inlet manifold 8WI through a 9 mm Inside Diameter ID nylon reinforced Tygon tubing At a distance of 0 3 m from the CAT the water passe...

Page 8: ...ware is installed from a single CD ROM via an Install Shield Wizard in the same manner as most Windows software The install shield Wizard will install the program in C Program files Dynamax HPFM There are five distinct parts to software installation allowing customers to leverage software created independently by Microsoft measurement computing USB software experts and Dynamax Inc Installation is ...

Page 9: ...d Parts and Packing List is included in Appendix I 1 5 What to Keep NOTE When unpacking do not discard the box and packing material Dynamax ships the HPFM in a box with material on all six sides This makes the shipping box the perfect box for you to ship your HPFM internationally across the U S or back to Dynamax for an annual calibration Also keep the Lists of Parts the software and the tools tha...

Page 10: ...t that you will be working with and measure the stem size Section 9 0 9 Cut the sample plants stem and install the Pressure couplings Section 9 0 Use 1 mm ID HPLC Natural light tan tubing with fittings 1 20 mm HPCC 1 4 HPCC 4 10 and HPCC 10 20 and 1 5 mm ID Teflon HPLC Clear tubing with fittings 19 50 mm HPCC 19 35 and HPCC 34 50 10 Determine the correct flow range to use for your selected sample ...

Page 11: ...ails Consequently the HPFM has been designed to measure K quickly before the above effects become serious enough to influence K Doing rapid measurement raises other sources of error that need to be addressed The rate of water flow into roots F will exceed the rate of passage through the roots Fh if the root is initially dehydrated since some of the water will remain behind to re hydrate cells But ...

Page 12: ...se where all of the air bubbles are near the outlet side of the flow meter we can equate Pb to P2 Pi Pi is the initial absolute pressure of the bubble when P2 0 Pi approximately equals 0 1 MPa The barometric pressure will determine the Pi There will also be a small contribution by the surface tension of the air water interface to bubble compression In the special case where the air bubbles are nea...

Page 13: ...ydraulic Resistance QSS During steady state measurements of QSS water flow and applied pressure are both constant and by definition the water flow into the object measured equals the flow out of the object In practice it is never possible to keep flow and pressure perfectly constant so it is best to refer to such measurements as quasi steady state The capillary tubes CT on the HPFM have been calib...

Page 14: ...and all other applications 2 Insert the HPFM3 CD in your CD drive Use Windows Explorer to browse to the root of the CD For Windows Vista and Windows 7 users 3 Right click Setup exe and select Run as administrator 4 Navigate to Start Menu Control Panel Add Remove Programs and check if Microsoft NET framework 3 5 or newer version is available on your PC NOTE For Windows Vista and 7 users Microsoft N...

Page 15: ...f upgrade is needed double click on dotnetfx35 exe in your CD directory and follow the instructions on the installation dial 6 After NET Framework 3 5 installation is completed double click on setup exe to install HPFM software ...

Page 16: ...atically install Security Key driver This USB device is used in conjunction with HPFM for security purpose Click OK to exit this screen when completed 9 Next the process installs the Measurement Computing MC hardware communication and analog data acquisition software InstaCal 10 A new self Extractor screen will pop up to ask your permission to continue the installation Click OK to proceed ...

Page 17: ...ill start which is essential to HPFM operation Click on Setup to continue 12 Click on Next and choose installation directory use default location 13 Windows will prompt you to restart your computer after installing all of the above products Click on Yes to restart ...

Page 18: ...FM and InstaCal icons on your desktop HPFM directory located at C Program Files Dynamax HPFM HPFM ini is a setting file which matches the calibration data supplied for your serial number and calibration document MC is directory located at C Program Files Measurement Computing DAQ ...

Page 19: ...dows XP 2000 Vista in order for HPFM to read pressure check and then copy if needed the CB CFG file from C Program Files Dynamax HPFM IcalUL CB CFG has been copied to C Program Files Measurement Computing DAQ For 64 bit Windows XP 2000 Vista copy the CB CFG file to C Program Files X86 Measurement Computing DAQ For Windows 7 copy CB CFG to C ProgramData Measurement Computing DAQ ...

Page 20: ...t to the Measurement Computing USB2404 UI device under the top of HPFM When prompted for New Hardware Found select Yes this time only and click Next Please select Install the software automatically Another screen will pop up to notify you that a new device has been detected click OK to add The USB carrier is the generic loader for the USB2404 device Click Finish when done ...

Page 21: ... Next Please select Install the software automatically USB2404 UI is the protocol for our HPFM Gen3 to communicate directly with the USB driven MC module as opposed to a USB driver that uses a COMx port The next time you plug in the USB cable to the A D converter there will be a message that the USB device is installed Now the green LED on the USB2404 UI unit should start blinking To review a prop...

Page 22: ... 18 After installing the device drivers open the InstaCal program from the desktop or the START menu Before actively using the icons the serial number must be highlighted Then click on Configure icon to confirm the settings ...

Page 23: ... Rejects DO NOT use any other timing modes in the list Temperature units Celsius Once these changes have been made click OK and proceed to the next step 20 While under CH0 settings make the following changes Channel Mode Bridge Bridge Type Full Bridge Range 62mv v Once these changes have been made click OK and proceed to the next step ...

Page 24: ...ode Bridge Bridge Type Full Bridge Range 62mv v Once these changes have been made click OK and proceed to the next step 22 While under CH2 settings make the following changes Channel Mode Thermocouple TC Type Type 2 Once these changes have been made click OK and proceed to the next step ...

Page 25: ...libration section for details on other pressure voltage comparisons A valid temperature in degrees C should appear as well Now that you have properly installed the program and configured the system you are ready to run HPFM 24 Double check your Calibration table This step is to ensure that correct calibration table is copied into your HPFM directory 25 Go to your CD ROM drive open HPFM ini from th...

Page 26: ...om CD and paste into the installed directory mentioned above and overwrite the existing HPFM ini document DO NOT make changes to this ini file The settings menu and the data viewer allows for editing the values if necessary Normally this is not required except by a certified Dynamax technician ...

Page 27: ... only for testing and bubble removal 3 Carefully follow the instructions in Section 5 4 5 2 Valve Setting for Preparing the HPFM for Service The valve settings are important in removing air bubbles gas and keeping the air from infiltrating the system at different points in the handling use and storage of the HPFM During the storage of the HPFM unit make sure that the purple outlet value is closed ...

Page 28: ... increase during the test Close the tank valve and release the hose pressure by pressing on the valve release needle WARNING Do not pressure the compressed air supply hose to above 690 kPa 100 PSI while the hose is disconnected Do not disconnect or connect the hose if the pressure is above 70 kPa 10 PSI The disconnects on the air pressure hose and HPFM system has a working pressure of 690 kPa 100 ...

Page 29: ...ate the rate of increasing pressure Close the Compressed Air Valve AV in Photo 4 page 34 when you have reached the required pressure in a range from 200 to 500 kPa 29 to 72 PSI WARNING Do not attempt to adjust or plug the safety relief valve If you are doing a transient pressure test release CAT pressure at 0 to 7 kPa 0 to 1 PSI and turn the pressure regulator screw until the outlet pressure is at...

Page 30: ...ittle Air will compress with great changes in the volume that the air occupies That large change is why air must be removed from the HPFM system The water added must have the air removed There are two accepted ways for removing the absorbed air from water The easiest way is to boil the water or raise the temperature of the water to the vapor point of water 100 C 212 F However boiling removes less ...

Page 31: ...n used proceed to Subsection 5 4 2 Priming a totally empty CAT The other method is to put water into a vacuum flask and draw a vacuum over the water for 5 to 10 minutes The steps for this procedure are 1 Place the distilled water in a vacuum flask Fill the flask to its logical level Do not over fill Distilled Water is convenient and easy to obtain It is even available in most food markets 2 Vacuum...

Page 32: ... tubing straight upward Depress the Refill Kit male disconnect against a hard object such as a flat blade screwdriver allowing the water to flow and remove bubbles from the Refill Kit tubing WARNING Take Precautions Use Gloves when handling the HOT Degassed Water 5 Connect the Refill Kit to the HPFM Once the connector is snapped shut turn the water valve to the left and proceed to using the follow...

Page 33: ...rn the valve to the right bleeding the air 3 Once the pressure is removed close the Compressed Air Supply Valve 4 Connect the Refill Kit to the HPFM using the following steps a Make sure that there is degassed water in the Refill Kit If not go to Subsection 5 4 1 Making Degassed Water Preventing Algae Buildup Inside the HPFM Make sure that you have enough water to finish the sampling project in th...

Page 34: ...5 Eliminating Air from the HPFM Before eliminating air from the HPFM for the first time study Photo 4 which gives the location of components on the HPFM The labels are AV Air Valve CAT Captive Air Tank GQ Green quick fit connector for adding air to CAT NV Needle Valve OQ Orange quick fit connector for adding water to CAT PT1 Pressure Transducer 1 on inlet side PT2 Pressure Transducer 2 on outlet s...

Page 35: ...s is to turn the HPFM unit the way the bubbles move into the water filter 7 If you cannot move the unit then loosen the hose clamp for tubing at the top of the CAT Hold the tubing in place while loosening the clamp Do not let go of the hose Allow the removal of the air bubbles and while holding the tubing in hand tighten the hose clamp 8 Wipe up any excessive water off of the HPFM 5 5 1 Purging Ai...

Page 36: ...ors mostly when measuring low conductance by the transient method when using the lowest three flow ranges i e the Green Orange and Red ranges The best way to remove air bubbles from the 8 Way valves is to perfuse water through the system overnight 12 hours after bleeding the manifold Steps for perfusing the water can be found in Subsection 5 4 2 Priming a totally Empty Captive Air Tank CAT The ste...

Page 37: ...ct the 1 5 m 5 ft Red HPLC tubing ID 0 0127 mm 0 0005 to the Flow Out Port of the HPFM Make sure that the Flow Out Manifold is closed You may also connect the Red HPLC tubing to the Teflon FEP hose that may already be attached to the Flow Out valve of the Manifold This can be accomplished with the HPLC Union included with the HPFM accessories c Open the Water Supply Control Valve to the right allo...

Page 38: ...auge to save battery power Also be sure to shut off the gas supply to the pressure regulator This will prevent gas loss from your supply tank in case of a slow leak CAUTION It is recommended that you keep the HPFM pressurized at 140 280 kPa 20 40 PSI with the outlet valve closed at all times when the HPFM is not in use a Open the Water Supply Valve to the flow position Photo 7 b Make sure that you...

Page 39: ...opened and closed See figure 3 Make sure the valves to the two pressure transducers are ALWAYS left open and that the outlet valve is closed except when water flow is desired To pressurize the system turn the AV to the fill position pointing left and adjust the needle valve NV so that the desired rate of pressurization is achieved normally 0 5 to 2 PSI per second To release pressure turn the AV to...

Page 40: ...pe in a Project Name Make a note if desired If opening a previous project select Existing Project tab choose the date when project was created Then click on Search button When done click OK to finish 6 3 Set Zero dP Transient Conductance Preparation 1 Choose Set Zero from the Analysis Type drop down menu then choose Brown range from the Set Flow Level drop down menu Open the brown 8WI 8WD Valves a...

Page 41: ...der regression will remove dP offsets across the range of a transient data sets a To Ignore points check the Set Ignore Points Box in the bottom left hand corner and then select the points you want to ignore b To delete points select the points you want to delete and click DEL c To retrieve deleted points click on the UNDO button in the bottom right hand corner d To undo the regression select the ...

Page 42: ...ly important to do prior transient measurements while the HPFM is connected to a solid metal or plastic rod the same diameter as the object you will measure See Section 3 Applications and Theory of Operation to understand what the data will look like when air bubbles are present Follow the instructions under Sub Section 5 5 Eliminating air from the HPFM to solve the problem 1 Adjust the needle val...

Page 43: ...lly begin As soon as the first points appears on the graph start the pressurization Start the flow of air into the CAT at the rate of 5 to 10 KPa per second as adjusted earlier with the needle valve Open AV to let the pressure increase Observe the LIVE DATA viewer and dials for the tank water pressure for approaching the maximum pressure Observe the flow rate dial to see if you are exceeding the c...

Page 44: ...xample of a typical graphical curve at the end of a transient is shown in Figure 7 7 If you are measuring a root quickly release the pressure so as not to change the root by continued perfusion Often the first transient is poorly shaped because of air bubbles or leaks or because the rubber in the compression fitting is shifting position So you will probably want to do one or two more transients on...

Page 45: ...o be ignored or deleted Usually you will ignore points below 100 kPa 6 Apply 1st order regression and click Yes to save regression values Note All regression temperature corrected K and standard temperature 25 C K are saved in the file named by the project managers with a trn extension See Sections 7 1 7 4 for more information ...

Page 46: ...lculating the slope That slope is the hydraulic conductance of the measured plant Choose Regression as the Analysis Type Click Start and Regression window appears Click Load Data navigate to the desired folder and choose your transient data to be analyzed Check Set Ignore Points box and select Choose Points to be Ignored Usually you should ignore all points below 100 kPa and points not fitting a s...

Page 47: ...Revision JUNE 2017 47 Or select Choose Min Max Points instead Choose 1st Regression Order and click Perform Regression button to finish Click Yes to save the regression ...

Page 48: ...wing a QSS measurement to stabilize and then use the AVERAGE button to store the running average of 10 most recent readings 6 6 1 Getting Started with QSS Before you start make sure that you have zeroed the pressure transducers according to Section 6 3 Set Zero dP Transient Conductance Preparation Setting the zero flow volts must be done at the start of each daily usage of the HPFM Make sure that ...

Page 49: ...Revision JUNE 2017 49 b Click on the STATIC OFFSET set the new value to zero and SAVE ...

Page 50: ...to the next highest range which would be the Orange range So you would open the valves corresponding to the Orange colored HPLC caps f Returning to the software click on the Orange flow level range and click the Start button You should see a decrease in the differential pressure and the software will stop warning you of an excessively high differential pressure 3 The working range for the differen...

Page 51: ...e more water flow within a given flow range if desired 5 Setting the STATIC OFFSET Static offset will occur electronic drift in the PT1 and PT2 and as mentioned in the QSS introduction a difference in the sample height can also introduce an offset The electronic offset can be removed by closing the outlet and reading the dP in the DATA VIEWER An offset at the sample can be removed by inserting a s...

Page 52: ... we note the dP is less than 1 and calculated zero flow in the data viewer Static offset is saved in the hpfm INI file and will be used for the next time HPFM is turned on or the flow analysis QSS only is restarted If one changes to a new flow range be sure to check or change the Static Offset ...

Page 53: ...click on the graphic window to bring up the menu To zoom in on a series of data point above and left of a part of the graph you want to enlarge and drag your pointer to a point below and to the right When you let go of the clicker the view inside that box will expand Zooming can be done by moving a scroll button either up or down for Zoom in or Zoom out Checking on the SHOW POINT VALUES allows one...

Page 54: ...s easier to click the Unzoom or set scale to default The default is the normal pressure range of HPFM Images are saved whenever you right click and select Save Image As This action will allow you to save images in six common image formats ...

Page 55: ...ilar temperatures If the sample is wet the evaporation can also lower the temperature below the air temperature 7 2 Corrections At Test Temperature HPFM Gen 3 has a built in sensor attached to the outlet manifold which records and logs temperature with all the flow and pressure data during calibration The data collected with all measurements are recorded in real time always The conductance values ...

Page 56: ...e In the case of temperature differences between samples taken one may want to make an additional correction For those cases where many different plants were measured at many different temperatures we suggest converting to a standard temperature for a direct comparison or for publications With HPFM Gen 3 the software computes the K25 the corrected conductance adjusted again from the reading temper...

Page 57: ...ow on the CD ROM Each file contains all of the data as well as your comments calibration used and the temperature corrected K values shown in the previous Sections 7 2 and 7 3 In the example below the QSS data file is opened with excel and converted directly from a csv to a file format that can be transferred to charts or other analysis programs ...

Page 58: ... air bubble But during quasi steady state measurements after 40 minutes of perfusion the bubbles are compressed to a quasi equilibrium volume where further volume change depends on the slow dissolution of the air in water The dissolution proceeds slowly over many hours in large stems Oak species contain lots of air in old wood so the transient conductance can be 2 to 4 times the quasi steady state...

Page 59: ...eaks in the 8WO and the compression fittings or it might be due to non linear elastic effects Clearly the 1 5 mm tube is preferable for measurements of conductance of an unknown and the slight slope on the plateau should be subtracted from any conductance calculated on an unknown 8 4 Air Bubbles Air bubbles in the compression fitting or base of stem will influence the accuracy of conductance measu...

Page 60: ...te and transient values of conductance show transient conductance more than 10 than the quasi steady state value then you probably have a stem with air more or less evenly distributed throughout the wood In Figure 14 this transient has been done on a 1 5 m length of Red tube 0 12 mm ID There is still a small air bubble present but the data are good enough to get a reliable conductance The transien...

Page 61: ...eat of the transient done above with a small air bubble in the 8W0 manifold The transient was re measured on the Red range The slope of this curve should still give a valid conductance although the bubble can be eliminated completely Figure 15 Transient re measured on the Orange range ...

Page 62: ...cise or cut the sample plant or tree Make sure that there are no anomalies such as grafting scars limbs old limb scars or excessive damage that might cause problems with the compression coupling creating a sealed system Keep in mind that the largest object that the HPFM can be connected to is 50mm with the included compression couplings Measure the object that you wish to sample and make sure that...

Page 63: ...e that the washer is as close to the size of the stem as possible The aluminum compression ring should still be easy to slip on or off 4 Place the rubber seal over the prepared area of the root stem The seal should be snug but should not have to be forced If the compression seal is too small use the next largest seal If the rubber seal is too big use a smaller one The rubber seal should be applied...

Page 64: ... slightly approx 1cm above the rubber compression seal If it does not remove the cone and compression fitting and remove more bark as per step 2 If the rubber compression seal closes around the end of the stem then an inaccurate reading may occur CAUTION Make sure to apply a light coating of G4 Silicone grease to the outside surface of the rubber seal This will prevent binding and eventual destruc...

Page 65: ...e still depressing water out to fill the displace ment of the needle itself Make sure that you have water on top of the open area of the HPLC connection with no air pockets below 9 Note the tubing you are using If you are using the smaller 1mm ID Natural HPLC tubing recommended for use with small compression coupling 1 20mm then you will need two large viton O rings with one small viton O ring for...

Page 66: ...at the pressure is 5 PSI 35 kPa Open the valves on the HPFM allowing the tubing to bleed the water at a slow drip as shown in photo 14 above This will remove air from the tubing g Place the tubing into the compression fitting on the top of the compression coupling and move the HPLC compression fitting cap down Make sure that the tubing stays solidly inside the acrylic cone of the compression coupl...

Page 67: ...h connecting large stems to compression fittings is that the fitting slips off during pressurization One way to prevent this is to obtain a few small wood screws and screw 2 to 6 of them between the end of the stem and the upper surface of the rubber stopper Leave the heads of the screws a few mm above the wood This will prevent the stopper from slipping past the screws The effect of the screws on...

Page 68: ...ssible for research The HPFM before moving must be prepared Preparation will keep the HPFM ready for the next sampling keeping air pockets or bubbles from entering into the HPFM system The steps for preparing the HPFM are a Close off the purple outlet valve on the 8WO and leave the CAT tank pressurized b Disconnect the Compression Coupling from the connecting tubing by loosening the HPLC cap on th...

Page 69: ...connection hold the tubing up to minimize the spillage of the degassed water Also make sure that the steel clamp is in place for the new water filter 5 Slide the filter down removing the water filter from the strap that is binding it to the frame 6 Hold the filter and with a slight twisting action remove the tubing from the bottom of the water filter Make sure that the steel clamp is in place for ...

Page 70: ...older of the HPFM CD Rom and printed for your convenience Below is the example of the calibration data and graphics Calibration Regression Data for HPFM 12 111 Tuesday February 28 2012 Calibration Factors NIST Pressure Calibration against certificate number C 1950 Date Time 2 27 2012 12 07 Index Pressure kPa PT1 mV PT2 mV 0 10 02 0 21382 0 2405 1 52 95 0 82739 0 86345 2 90 08 1 3564 1 40098 3 130 ...

Page 71: ...Revision JUNE 2017 71 Green Range Zero flow evaporation at 4 73 e 09 Calculated A0 7 59 e 09 A0 with evaporation considered 2 86 e 09 ...

Page 72: ...Revision JUNE 2017 72 Orange Range Zero flow evaporation at 4 73 e 09 Calculated A0 2 84 e 08 A0 with evaporation considered 2 36 e 08 ...

Page 73: ...Revision JUNE 2017 73 Red Range ...

Page 74: ...Revision JUNE 2017 74 Yellow Range ...

Page 75: ...Revision JUNE 2017 75 Grey Range ...

Page 76: ...Revision JUNE 2017 76 Brown Range ...

Page 77: ...Revision JUNE 2017 77 Zero Adjustment Measurement ...

Page 78: ...coupling 13 1 HPCC36 55 34 50 mm compression coupling 14 2 10 20 mm aluminum compression rings 15 3 19 35 mm aluminum compression rings 16 3 34 50 mm aluminum compression rings 17 6 6 1 2 Coupling seals drilled 18 9 10 Coupling seals drilled 19 9 13 Coupling seals drilled 20 1 G4 Silicone coupling assembly grease 21 1 2000 PSI regulator only for HPFM C 22 1 B 4 HN HEX nipple installed on regulator...

Page 79: ...A D circuit OQ orange quick fit Swagelok connector for adding water to the CAT GQ red quick fit Swagelok connector for connection to Pressure Regulator PT1 Pressure Transducer 1 on inlet side PT2 Pressure Transducer 2 on outlet side 8WI 8 way manifold on inlet side 8WO 8 way manifold on outlet side IV Flow Inlet Valve on inlet 8 way valve OV Flow Outlet Valve on outlet 8 way valve DP Digital Press...

Page 80: ...open all the valves on manifolds except outlet valve and open water valve as well this usually being ignored and could costs you hours try to figure out why it didn t work Then switch on your HPFM system and run HPFM software Go to File Calibrate HPFM A D Setup and click Start Stop Increase tank pressure to about 400 kPa and you will be able to see a reading in the window The DP reading should be ...

Page 81: ...e C T theory and the evidence that the Scholander Hammel pressure bomb measures xylem pressure potential Px correctly because much of the evidence for the C T theory depends on pressure bomb data 55 Tsuda Makoto and Tyree M T 1997 Whole plant hydraulic resistance and vulnerability segmentation in Acer saccharinum Tree Physiology Vol 17 pp 351 357 Hydraulic properties were studied in Acer sacharinu...

Page 82: ...us robur L saplings In the first experiment conductances were measured with the HPFM on excised shoots and detopped root systems In the second experiment the impact of temperature induced changes in groot on sapling transpiration E and leaf water potential was assessed Intact plants were placed in a growth cabinet with constant air and variable soil temperatures The results illustrate the signific...

Page 83: ...rtant to prevent air bubbles from entering the Captive Air Tank CAT because these bubbles will re saturate the degassed water Cubic Feet Cu Ft The compressed air tank for the HPFM has a volume of 24 cubic feet Differential pressure dP Water flow across the selected CT causes a differential pressure dP drop dP P1 P2 measured with PT1 and PT2 respectively If the software recognizes that the differen...

Page 84: ... pressurized water flows from the CAT to the 8 Way Inlet manifold 8WI Flow Inlet Valve IV on inlet 8 way valve K uncorrected conductance kPa Measurement for pressure in Kilo Pascal s K root conductance Kr KCT Conductance of the capillary tubes LPT1 LPT2 or LPT3 A connection used to connect the HPFM to a PC When the HPFM program starts the program automatically tests for basic communication with th...

Page 85: ...T Quasi steady State Measurements of Hydraulic Resistance RQS During steady state measurements of RQS water flow and applied pressure are both constant and by definition the water flow into the object measured equals the flow out of the object Unknown hydraulic resistance RU The unknown hydraulic resistance of a quasi steady state measurement Supply Box SB For storage of small parts and location o...

Page 86: ... WV Allows water flow into the filter and subsequently into the valve manifold 8WI and 8WO system at P2 0 8WI An Omnifit 8 Way HPLC valve of octagonal geometry with 8 tubes emerging from a common point in the center and each tube terminated by a valve 8WO An 8 way manifold on outlet side ...

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