Decagon Devices SC-1, Operator'S Manual

Page 1: ...L e a f P o r o m e t e r Operator s Manual Version 8 ...

Page 2: ...Inc 2365 NE Hopkins Court Pullman WA 99163 Tel 509 332 2756 Fax 509 332 5158 www decagon com Trademarks Leaf Porometer is a registered trademark of Decagon Devices Inc 2005 2010 Decagon Devices Inc All rights reserved ...

Page 3: ...Components of the Leaf Porometer 5 Keyboard Functions 6 The Sensor Head 7 Setting the Time 8 Calibration Number 8 Manual Mode vs Auto Mode 9 Precautions 10 3 The Menus 11 The Measurement Menu 11 Measuring Small Leaves Needles 13 Taking a Measurement in Auto Mode 13 Taking a Manual Mode Measurement 15 Saving Data 16 Averaging Readings 18 Measurement Troubleshooting 18 Measurement Precautions 19 The...

Page 4: ...me 50 Calibration Number 50 Retrieving Leaf Porometer Information 51 The Menus and Their Functions 52 6 Leaf Porometer Theory 58 Stomatal Conductance 58 How the Leaf Porometer Works 58 7 Care and Maintenance 68 Changing the Batteries 68 Cleaning the Sensor Block 68 General Precautions 72 Upgrading Firmware 72 8 Troubleshooting 75 Further Reading 83 CE Compliance 85 Appendix A Send Feedback 86 ...

Page 5: ... Porometer Customer Support When contacting us via fax or e mail include your Leaf Porometer s serial number this can be found on the inside of the battery cover the firmware version you are currently using your name address phone and fax number and a description of your problem Phone United States Canada toll free 1 800 755 2751 Outside of the U S Canada 1 509 332 2756 Fax 1 509 332 5158 E Mail s...

Page 6: ...r things of whatsoever kind includ ing but not without limitation loss of anticipated profits occasioned by or arising out of the installation operation use misuse nonuse repair or replacement of said material and equipment or out of the use of any method or process for which the same may be employed The use of this equipment constitute s Buyer s acceptance of the terms set forth in this warranty ...

Page 7: ...nd department of the person responsible for the instrument as well as a description of the problem This will better help our technicians and shipping depart ment to expedite repair on your Leaf Porometer and ship it back to you Please pack your Leaf Porometer carefully Ship it back in the carrying case preferably inside a cardboard box Ship to Decagon Devices Inc 2365 NE Hopkins Court Pullman WA 9...

Page 8: ...umidity measurements between them It can display information in three selectable units mmol m2 s millimoles per meter squared seconds m2 s mol meters squared seconds per mole s m seconds per meter The first is a unit of conductance while the other two are units of resistance To change between them use the arrow keys when taking a reading see Making a Measurement pp 16 They can also be altered by u...

Page 9: ...view of the Leaf Porometer The Leaf Porometer features an easy to use six button menu driven interface There are three primary menus the Main Menu Data Menu and Configuration Menu See Menus Chapter 3 You can navigate between each of these by pressing the Menu button Components of the Leaf Porometer The Leaf Porometer and its components come to you in a foam padded carrying case You should find the...

Page 10: ...Porometer Operator s Manual 2 About the Leaf Porometer 6 Calibration plate Bottle of distilled water Tweezers Calibration filter paper disks Keyboard Functions Here is a brief overview of each key s function ...

Page 11: ...ical values in sub menus as well as select different units Holding down an arrow key allows you to scroll between dif ferent options quickly Escape This key backs out of sub menus and can be used to cancel certain actions Enter This key is used to make selections within menus and sub menus and also begins taking measurements The Sensor Head The Leaf Porometer cannot take measurements without the a...

Page 12: ...ensor head comes with a default five digit calibration number that can be found on the tag on the sensor head cable and on the calibration certificate This default calibration number has been entered into the leaf porometer readout unit and will be applied to each measurement until a user initiated calibration is performed When a user initiated calibration is performed a new calibration number is ...

Page 13: ...amount of time necessary to reach steady state conditions is proportional to the conductance At conductances less than 20 mmol m 2s 1 steady state con ditions are generally reached in less than 5 minutes At higher conductances steady state conditions can take up to 30 minutes Please note that leaving the sensor head on the leaf surface for more than a few minutes can cause the sto matal conductanc...

Page 14: ...ing leaf and begin the Auto Mode measurement the measured stomatal conductance must reach 5 mmol m 2s 1 So if you are making measurements on leaves with extremely low conductances it may be necessary to make the measure ments in Manual Mode Precautions Before using or calibrating the porometer remember Avoid leaves that are wet or heavy with dew never take readings in the rain Do not touch the Tef...

Page 15: ...ber at left and the currently selected unit of measurement at right Below are two columns of numbers The left is the sensor closest to the leaf and the right is the sensor farthest from the leaf Each column has the temperature of that sen sor and its percent humidity The Leaf Porometer uses these to calculate the stomatal conductance value see How the Leaf Porometer Works in Chapter 5 Making a Mea...

Page 16: ...ortant If you do not you can expose the Teflon disk to extra humidity and cause inaccurate readings The pictures below illustrate the correct way to hold the exter nal sensor Correct Incorrect Once you are holding the sensor head properly place it on the leaf as shown below NOTE It is important to consider if you will be measuring adaxial conductance on the top of the leaf or abaxial the bottom Si...

Page 17: ...s shown below This is because sin gle needles or small leaves including blades of grass may not adequately cover the apature of the sensor Taking a Measurement in Auto Mode There are two modes in which to make measurements Automatic and Manual The following illustrates how to make a measurement in Auto mode Caution Before using allow the sensor to equilibrate to the ambient temperature ...

Page 18: ...press Enter to begin a reading 3 After pressing Enter the following screen will be displayed 4 The reading will begin once the sensor head is placed on a leaf and a conductance value greater than ambient is detected A progress bar will also indicate the reading is underway If the following screen appears when you press Enter open the sensor and gently wave it in the air You should not blow into th...

Page 19: ...y seconds remain 6 Once the time limit has expired the porometer will dis play the final conductance You may save or discard your data See Saving Data on the next page for instruc tions Taking a Manual Mode Measurement Caution Before using allow the sensor head to equili brate to the ambient temperature 1 Select Manual mode from the Configuration Menu Please note that manual mode is only for speci...

Page 20: ...or taking readings and the elapsed time is displayed directly below the system time 4 You may save your data at any point during the reading by pressing Enter See below for instructions on how to save your data Saving Data In Automatic mode you can save data as soon as the timer has expired in Manual mode you save your data without interrupting your reading To save your data in either mode 1 The f...

Page 21: ...ading 3 Select Annotate and press Enter to give your data a file name 3 How to annotate a reading Selecting Annotate will cause the following screen to appear You will see a series of lines with a set of arrows above and below the first If you have annotated a previous reading the old annotation will remain to be changed or deleted Use the arrow keys to select a letter or number and press Enter to...

Page 22: ... of readings from dif ferent positions on the plant The average is proportional to the type of readings taken For example if you know your plant receives 70 sunlight you might consider taking seven readings from the sunny part and three from the part in the shade You can also obtain the average readings for a field of plants For example if you had a field of corn you might decide to take a reading...

Page 23: ...nstrument 0 to 1000 mmol m2 s an approximate symbol will appear to the left of the read ing If the stomatal conductance reaches a value greater than or equal to 6000 mmol m2s an infinity symbol is shown in place of the measurement Most often the excessively high values are caused by water on the leaf surface If you consistently are getting high readings check your leaf sur face for the presence of...

Page 24: ...ings Chemical Effects Chemical vapors can interfere with the polymer layers used to form the humidity sensors These fumes can diffuse through the sensor and throw off the sensor s accuracy It is a good idea therefore to never bring the sensor into con tact with any sort of chemical vapor i e glue alcohol gaso line foam See section on Sensor Head Reconditioning if you suspect your sensors have been...

Page 25: ...r that will cause the stomatal conduc tance to change is the humidity at the leaf s surface As the outside humidity increases the stomata will open Porome ters that dry the air around the stomata decrease conduc tance likewise those that allow surface humidity to increase do the opposite Carbon Dioxide CO2 One purpose of the stomata is to regulate the leaf s usage of CO2 which is important to con ...

Page 26: ...r s memory This menu features three sub menus View Here you can view measurement data stored on your porometer To do this 1 Press Enter to select the view sub menu 2 For each measurement you will see the time acquired stomatal conductance resistance value depends on which unit you have set as your default and its annotation if that measurement was saved with an annotation ...

Page 27: ...f you are unable to use the Leaf Porometer Utility you can use terminal software to transfer the data from your porom eter to your computer The following steps should apply to most terminal software programs 1 Configure your terminal software with the following settings 9600 baud 8 data bits 1 stop bit no parity No software hardware flow control Append line feeds to incoming line ends Echo typed c...

Page 28: ...e permanently deleted from the Poromter and cannot be recovered To erase data 1 Press Enter to select the Erase sub menu The following screen will appear 2 Press Enter again to erase the memory or ESC if you decide not to erase the data Erasing will be displayed as data is being removed which usually takes about 6 seconds 3 When this is complete you will be returned to the Data Menu ...

Page 29: ... the appropri ate units for your readings and view information about your Leaf Porometer There is also a battery icon to the right indicating how much battery power is currently avail able This menu features seven sub menus Calibration See Chapter 4 for a thorough explanation of the calibration menu Date 1 To change the current date Press Enter to select the Date display ...

Page 30: ...row keys to change this number Holding down the up down arrow will allow you to scroll quickly between values 4 Press Enter to move to the next value and repeat step 3 If you need to return to the previous number press Escape 5 When you have finished changing the last number press Enter and you will be returned to the Configuration Menu Time To change the current time 1 Press Enter to select the T...

Page 31: ...ollquickly between values 4 Press Enter to move to the next number and repeat step 3 If you need to return to the previous number press Escape 5 When you have finished changing the last number press Enter and you will be returned to the Configuration Menu Mode The Mode Menu allows you to choose which type of mea surement mode to use in the Main menu Press Enter to select a mode See the end of Chap...

Page 32: ...tinuously measures conductance and updates the screen This mode is only suitable for low conductances 20 mmol m 2s 1 The user can decide when equilibrium has been reached Pressing Enter will give you the option to save your data at any point during the reading Units Data in the Leaf Porometer can be displayed in three units These can be accessed on the Main Screen as well as under the Configuratio...

Page 33: ...This menu allows you to alter the screen contrast settings To access it use the Down arrow key to scroll to it and press Enter The following screen will appear Use the arrow keys to alter the contrast level Press Enter to save or Escape to cancel adjustments ...

Page 34: ...Leaf Porometer Operator s Manual 3 The Menus 30 About Screen This menu displays your Leaf Porometer s serial number and firmware version ...

Page 35: ...e porometer be calibrated every day that it is used or every time it is used under a different set of environmental conditions i e 15 C temperature change or 20 humid ity change Visit our website at www decagon com porocal for an online video tutorial of the calibration process Requirements All Leaf Porometers with firmware Revision 1 30 or greater have the ability to be calibrated by the user If ...

Page 36: ... equilibrium with the environment where measurements will be taken If you bring the porometer from an air condi tioned environment into hot field conditions it can take 10 minutes or more for thermal equilibrium to be reached You can check for thermal equilibrium by putting the porometer in manual mode and monitoring temperature readings until they are steady 2 Start Calibration To start calibrati...

Page 37: ...in thermal equilibrium with its surroundings see 1 above Press Enter to move to the next step 4 Enter Serial Number You will be prompted to enter the sensor head serial num ber This number can be found on a tag attached to the sensor head Select the number by pressing the up and down arrow keys to select a number and pressing enter after each digit ...

Page 38: ...hat the two sensors in the sensor head agree well with each other For the sensors to agree the air in the diffusion path should be well mixed Holding the Sensor Head Holding the sensor head in the correct manner is very important If held incorrecly water vapor from your fingers can expose the Teflon disk to artificially high humidity and cause inaccurate readings The pictures below illustrate the ...

Page 39: ... Once the sensor readings stabilize and are confirmed to be within 2 relative humidity of each other the calibration routine automatically advances to the next screen If the sensors don t equilibrate to similar humidity values check for water on the sensor head or on the Teflon filter If no water sources are found then the sensors may have been chemically contaminated or be otherwise malfunctionin...

Page 40: ...lter paper is critical for an accu rate calibration The paper must be wet enough to provide a 100 humidity surface but must not be too wet If the paper is too wet free water will be pulled into the hole on the calibration plate by surface tension and will change the effective dimensions of the hole thereby changing the con ductance The best method of ensuring the proper wetness state is to use the...

Page 41: ...urn the calibration plate over and carefully examine the hole to make sure that no meniscus of excess water is present in the hole If excess water is observed remove the filter paper dry the calibration plate and repeat the wet and flick procedure with a more aggres sive flick You should not have to re wet the filter paper during the calibration procedure However if the filter paper becomes too dr...

Page 42: ...libration plate into the sensor head making sure you ve oriented the side of the plate marked Metal Block toward the alumi num block side of the sensor head Be sure that the calibration plate is inserted until the alumi num block is seated firmly against the hard stop on the cali bration plate Correct Incorrect ...

Page 43: ...ydrate on the calibration plate for three min utes During this time the sensor head should not be removed from the calibration plate The progress of the hydration period can be tracked on the indicator bar at the bottom of the screen and the timer in the top right corner 9 Orienting the Sensor and Calibration Plate Once the hydration a calibration measurement or a regular measurement begins it is ...

Page 44: ...ad from the calibration plate open the sensor head and wave the sensor head in the air to mix the air in the diffusion path You can use the spacer pin to hold open the sensor head if desired As the sensors come to ambient conditions you should see the indicator bar move closer to the AMB line Once the sensors have equilibrated to ambient conditions the Attach Sensor Head screen will automatically ...

Page 45: ...e status of the calibration measurement Once the measurement is finished you will be prompted to Equilibrate Sensors 10 above and then Attach Sensor Head 7 above This will begin another calibration measurement The leaf porometer will continue to take calibration mea surements until three consecutive measurements are all within 7 5 of each other This ensures that the porometer is well hydrated and ...

Page 46: ... t achieve a good calibration then contact Decagon for help support decagon com 13 Calibration Complete Once the calibration is complete the new calibration num ber is automatically saved into the handheld unit and the following screen is displayed At this point you are ready to take measurements with your leaf porometer Note that the most recent saved calibration number will be applied to all sub...

Page 47: ...asurement menu and make a measurement on the calibration plate The measured conductance should be close to 240 mmol m 2 s 1 Please note that the first 2 3 measurements after the sensors have not been used for a while will be significantly low due to sensor dehydration and that the first two mea surements after re wetting the filter paper will also be inac curate due to thermal disequilibrium ...

Page 48: ...nterfacing with the Leaf Porometer Use this pro gram to download measurement data to your computer erase the Leaf Porometer s data set the date and time and see information about your Leaf Porometer SYSTEM REQUIREMENTS To use the Leaf Porome ter Utility you must meet the following minimum system requirements Microsoft Windows 98 or NT 4 SP 5 or better Intel Pentium Pro or better processor ...

Page 49: ...me downloads php Downloading Your Data This will transfer all saved measurement data on the Leaf Porometer to your computer Do the following 1 Make sure the RS 232 cable is connected to the Leaf Porometer and to a serial communication COM port on your computer 2 Open the Leaf Porometer Utility 3 Choose the appropriate COM port from the Use com puter communication port control on the main screen 4 ...

Page 50: ... choose between the fol lowing formats Microsoft Excel Workbook xls Text Tab delimited txt CSV Comma delimited csv Raw data Comma delimited txt 6 Click Save to download your data to the specified loca tion The progress bar shows the status of the download process NOTE You can cancel a download in progress using the cancel but ton If you cancel no downloaded data are saved ...

Page 51: ... Local settings found in the Control Panel under Regional and Language Options Regional Settings in Windows 98 You may override this and set the format to day month year by going to the Edit Menu click Preferences Units tab and by clicking Use tem plate under Date Time Format for Data Files Scan Records Scan records have additional columns than other data records They show a snapshot of the sensor...

Page 52: ...meter and cannot be recovered To erase your data do the following 1 Make sure that the RS 232 cable is connected to the Leaf Porometer and to a COM port on your computer 2 Choose the appropriate COM port from Use computer communication port control on the main screen 3 Click Erase in the lower left hand corner or Erase Data in the File Menu If you encounter an error message after clicking this but...

Page 53: ...ration Number Sensor Calibration Number screen You can use the Leaf Porometer Utility to enter a calibra tion number for the external sensor To do this go to Actions Set Sensor Cal Num The above screen will appear Enter the desired calibration number then click OK All five numbers must be entered even if the first number is a zero If the number is not correct an error message will be displayed Not...

Page 54: ... Choose View Porometer Information from the Actions Menu to see information about your Leaf Poro meter Leaf Porometer Information screen If you encounter an error message after clicking this button please refer to the Troubleshooting section for instructions This is a good way to find the serial number firmware ver sion battery status and number of stored measurements for your Leaf Porometer ...

Page 55: ...gs and settings on the Leaf Poro meter Below is a brief overview of the options each menu contains File Download Data Saves measurement data stored in your Leaf Porometer as a data file on your computer see instructions above Erase Data Erases all data in your Leaf Porometer see instructions above Exit Quits the program Edit Preferences This consists of three sections ...

Page 56: ... will save all downloaded measure ment data in the units used on the Leaf Porometer You can also choose to override the set tings in the Leaf Porometer and save your measurement data in one of three units mmol m2 s stomatal conductance millimoles per meter squared seconds m2 s mol stomatal resistance meters squared seconds per mole s m stomatal resistance seconds per meter ...

Page 57: ...te Time Temperature for saved data files This feature is on by default It does not apply to raw data files which do not have column headers Date Time Format Here you can set the format the date and time will be displayed in saved data files By default the program will use Windows Regional and Language Options accessible in the Control Panel in Windows the system settings on your computer 2 Communi...

Page 58: ...ly try re sending communications commands up to 10 Maximum Baud Rate You can set the maximum baud rate for talking to your Leaf Porometer Choose a lower baud rate if you are not getting reliable communications from your device Force Find all Communication Ports This will detect all COM ports on your computer and should be used if your serial to USB adapter does not appear in the drop down menu 3 A...

Page 59: ...it See instructions above for set ting this manually Error Log File This adds more troubleshooting mes sages to the error log which can be sent to Decagon Actions Set Porometer Date Time See the section on Setting Date and Time above Set Sensor Cal Num Here you can set the sensor head s cali bration number See page 35 View Porometer Information This shows the serial number firmware version the num...

Page 60: ...he user with a way to submit feedback to Decagon Check for Utility Updates Goes online and checks for utility updates Check for Firmware Updates Goes online and checks for firmware updates for the Leaf Porometer controller About Displays the current program version and Decagon contact information ...

Page 61: ...af Porometer measures the stomatal conductance of leaves by putting the conductance of the leaf in series with two known conductance elements By measuring the humidity difference across one of the known conductance elements the water vapor flux is known The conductance of the leaf can be calculated from these variables We know the humidity at three places inside the leaf and at both of the humidit...

Page 62: ...2 The mole fraction of vapor at node 2 gs Stomatal conductance of the leaf surface gd1 Vapor conductance of the diffusion path between leaf surface and node 1 gd2 Vapor conductance of the diffusion path between node 1 and node 2 d1 Distance between the leaf surface and the first humidity sensor d2 Distance between the two humidity sensors 1 ˆ 2 2 1 1 2 a s r a s r atm vapor vapor T e h T e h P d D...

Page 63: ...1 Where the C s are related to relative humidity by 2 where hr is the relative humidity es Ta is the saturated vapor pressure at air temperature and Patm is atmospheric pressure Saturated vapor pressure is calculated by the Tetens formula with appropriate coefficients for water vapor 3 NOTE T must be in degrees Celsius Next we must determine the value of gd2 by the equation 4 2 1 2 C C g F d vapor...

Page 64: ...ps out Using these C and g values we can now solve equation 1 for the flux 8 Now that the vapor flux has been determined the stomatal conductance gs can be found This requires some assumptions First we assume that the relative humidity within the leaf tissue is 1 0 so by equation 9 75 0 5 2 5 75 1 15 273 10 12 2 6 44 ˆ 10 12 2 3 101 15 273 15 273 3 101 3 101 15 273 15 273 3 101 6 44 ˆ T x D Then s...

Page 65: ...dity sensor The sensor block head has been constructed from aluminum to eliminate the temperature difference This means that we can write equation 1 for node 1 and the leaf node and then set it equal to equation 8 10 11 12 Solving for gs d1 13 1 1 C C g F leaf d s vapor 1 1 1 1 1 r a s atm d s vapor h T e P g F ˆ 1 1 2 2 1 1 2 1 1 1 a s r a s r atm r a s atm d s T e h T e h d D P h T e P g ρ 1 ˆ 1...

Page 66: ...small the humidities are nearly the same and the denominator of the denominator of eq 6 goes to zero causing problems Multiplying top and bottom by the denominator gives 17 NOTE The resulting gs is in units of mol m2s 1 1 1 1 1 d d s s g g g D d T e h T e h D d h T e g a s r a s r r a s s ρ ρ ˆ ˆ 1 1 1 2 2 1 1 2 1 1 1 2 2 1 1 2 1 1 1 ˆ d T e h T e h d h T e D g a s r a s r r a s vapor s ρ 1 2 2 1 ...

Page 67: ... to the flux of water vapor which is proportional to the vapor pressure difference between 1 and 2 The effect of this cooling is to reduce the apparent humidity at the evaporating surface The actual vapor pressure at the evaporating surface is 18 Where s is the slope of the saturation vapor concentration function The temperature difference can be computed from an energy balance for the evaporating...

Page 68: ...c heat of air And 21 Substituting this into eq 18 gives 22 The vapor pressure difference between the leaf surface and the first humidity sensor then becomes 23 atm H p d ao a P C C C C g c g T T 1 2 1 2 1 2 1 γ γ λ 2 d H p g g c λ γ 2 2 1 1 1 a s r a s r T e h T e h 1 1 γ s T e e a s o 1 1 1 1 1 1 r a s a s o h T e s T e e e γ ...

Page 69: ...endence but their ratio is a weak linear function of temperature so the final form of the equation for q gives a value which is fairly constant with temperature though the temperature correction is made in code At room temperature a value of q 0 1 appears to work well 1 1 2 1 1 1 1 1 ˆ d d h q T e D g r a s vapor s ρ 10 3 4 071 0 4 1 1 γ γ γ atm a s atm atm a s P T x T e P sP T e s q ...

Page 70: ...of the screen 1 Carefully turn over the Leaf Porometer and locate the battery cover 2 Place your thumb on the grooves and push upward to loosen the cover 3 Remove the old batteries and insert new ones Be sure to orient the fresh batteries properly 4 Use the Leaf Porometer or the Leaf Porometer Utility to update the time and date Cleaning the Sensor Block It is necessary to clean the Sensor Block p...

Page 71: ... the sensor head open and use a dry swab to clean out the diffusion path Swabs are included with your kit Do not use a damp swab alcohol or other organic liq uids to clean the diffusion path Direct contact with water on the sensors as well as chemical vapors can cause damage 3 Reinsert the Teflon Disk Remember to handle around edges as much as possible Use something dry to press the filter complet...

Page 72: ...to see if the area you will be applying has dirt or soil particles as these can prevent the adhesive from applying fully You might try wiping the area with a slightly damp cloth before applying the new seal Replacing the Teflon filter disk A spare set of Teflon fil ter disks have also been included To replace the disk use a sharp object and carefully remove the disk Then handling the disk around t...

Page 73: ... and cable into an oven with good temperature control 4 Bake the sensor head in dry heat at 80 C for at least 24 hours 5 Remove the sensor head and let cool 6 Re hydrate the sensor head by exposing it to 70 80 rela tive humidity at 20 35 C for 12 hours A 75 humidity atmosphere can be conveniently generated by a saturated NaCl solution To hydrate with saturated NaCl the porometer head should be pla...

Page 74: ...here is excess humidity or dirt present Do not touch the Teflon disk Touching it will offset your readings Let it dry for 24 hours or until the ambi ent humidity reading returns to normal While this device is water resistant do not use it in rain and do not use it on leaves covered with dew or water droplets Upgrading Firmware From time to time Decagon will release firmware updates for the Leaf Po...

Page 75: ...are update so make sure to download any data you wish to save before loading new firmware Do not turn off or disconnect your instrument from the communications port while the firmware is updat ing Updating Firmware 1 Open the firmware updater application 2 Connect you Leaf Porometer to an available communica tions port on your computer ...

Page 76: ...lect the same communications port in the drop down list on the firmware updater application 4 Click Start to begin updating the firmware 5 Wait for the firmware updater to finish before discon necting your Leaf Porometer and closing the firmware updater application ...

Page 77: ...at may occur If these remedies still don t resolve your problem then please contact Decagon for help see Customer Support in Chap ter 1 Here is a list of some problems that may occur NOTE If you purchased your Decagon instrument from one of our international distributors please contact them for local service and support Troubleshooting Quick Guide If this problem occurs Refer to Instrument won t t...

Page 78: ...nductivity is not as expected Problem 13 1 PROBLEM Instrument won t turn on SOLUTION Make sure that the batteries are inserted correctly and or if they have enough power to activate the machine 2 PROBLEM The display is difficult to see SOLUTION Turn off the Leaf Porometer and then turn it on again If this does not fix the problem the Leaf Porometer features a built in screen for changing screen co...

Page 79: ...en continues to reappear it is possible that the cable or sensor is faulty and needs to be replaced To expedite the troubleshooting process save a Scan record by pressing Enter and then contact Decagon for further options 4 PROBLEM Message on screen displays the following SOLUTION The batteries in the instrument may not be properly inserted in the battery holder or they may need to be replaced If ...

Page 80: ...rmware onto an instrument this message may appear Navigate to the configu ration menu and verify that the date and time are set properly 6 PROBLEM Message on screen displays the following SOLUTION This screen will only be displayed when manually entering a calibration number The best solution to this problem is to perform a user initiated calibration Another option is to enter the default calibrat...

Page 81: ...to the Leaf Porometer or to stop this message from displaying the instrument must be serviced by Decagon 8 PROBLEM Message on screen displays the following SOLUTION This screen means that your firmware was not loaded prop erly and that an update is needed The firmware for the Leaf Porometer is user upgradeable To obtain this visit Decagon s website to see if new updates are available if not ...

Page 82: ... another application but I don t think any other programs are running SOLUTION Some PDA synchronization software monitor serial com munication ports Disable Microsoft s ActiveSync or Palm s HotSync system software while using the serial port with the Leaf Porometer Utility 10 PROBLEM My USB to Serial adapter is not showing in the communica tion port picker SOLUTION Enable Force find all Communicat...

Page 83: ...s 12 PROBLEM No information is being displayed SOLUTION Any conductivity that is lower that 5 mmol m2 s1 will not be displayed in Automatic mode Therefore check to see what mode you re in before beginning It is advisable to use Man ual mode if you know that your leaf has a conductivity that is lower than the minimum threshold for Auto mode Also remember that you must press Enter in Automatic mode ...

Page 84: ...gin a calibration If you re still having problems the inside of the sensor assembly may be dirty Remove the Teflon disk and clean it thoroughly see Chapter 7 The Teflon disk also may either be wet or dirty and may need to be dried out or replaced Additionally if your sensor was exposed to any out gassing materials it may require repairs or re conditioning ...

Page 85: ...Envi ronmental Biophysics Springer Verlag New York Heidelberg Berlin Second Ed 1998 pp 90 92 Jones H G Plants and Microclimate Cambridge University Press Cambridge 1983 Marshall B and Woodward F I Instrumentation for Envi ronmental Psychology Cambridge University Press Cambridge 1985 Pearcy R W et al Plant Physiological Ecology Field Methods and Instrumentation Chapman and Hall New York London 198...

Page 86: ...vices Inc Type of Equipment Leaf Porometer Model Number SC 1 Year of First Manufacture 2005 This is to certify that the Leaf Porometer manufactured by Decagon Devices Inc a corporation based in Pullman Washington USA meets or exceeds the standards for CE compliance as per the Council Directives noted above All instruments are built at the factory at Decagon and perti nent testing documentation is ...

Page 87: ...Send Feedback 83 Appendix A Send Feedback Decagon Software makes it easy to send feedback bug reports and feature requests to Decagon or your Decagon Distributor Choose Send Feedback to Decagon from the help menu This opens the window shown below ...

Page 88: ...dback If you are reporting a bug it is very helpful for you to tell us what steps you took for the bug to happen and any error message you saw By default bug reports also include the software error files You can send Decagon a file using this form too This is useful for sending data files that you have questions about If you work directly with a Decagon representative put their E mail address in t...

Page 89: ...6 Arrow keys 7 Automatic mode 28 Averaging readings 18 B Batteries changing 68 Batteries type 5 Button descriptions 6 C Carbon dioxide 21 CE compliance 84 Comm ports force find all 55 Configuration menu 25 Contrast adjusting using the contrast menu 30 D Data menu 22 Date 25 Downloading data 23 E E mail 1 ...

Page 90: ...rrect hand position 12 34 F Fax number 1 Further reading 84 G General precautions 72 H How the Leaf Porometer works 58 Humidity 21 L Leaf porometer utility command retries 55 maximum baud rate 55 measurement units for data files 53 Leaf porometer utility auto clock synchronize 56 downloading data 46 edit menu 52 erasing data 49 error log file 56 help menu 57 retreiving status information 51 saved ...

Page 91: ...l mode 28 Material Safety Data Sheet 37 Measurement saving 17 taking in automatic mode 13 taking in manual mode 15 Menu key 7 Mode selecting 27 P Phone number inside the U S Canada 1 Phone number outside the U S Canada 1 Power key 7 R Repairs instructions 2 S Seller s liability 2 Send Feedback 86 Specifications 4 Stomatal conductance explanation of 58 ...

Page 92: ...Leaf Porometer Operator s Manual Index 92 T Tech support 1 Temperature 21 U Units explanations of 4 V Viewing data 22 W Warranty 1 ...