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LI-COR li-6262, Инструкция по эксплуатации

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Section 3

3-12

Theory of Operation

It is often necessary to correct the CO

2

 mole fraction for differences in water

vapor mole fraction in sample and reference cells when CO

2

 and water vapor

are measured together.  An apparent CO

2

 mole fraction difference will

develop if water vapor is added to or removed from either air stream whether
a net CO

2

 flux is present or not.  This dilution effect can be removed when

the Vapor Flag (FCT 76) is set to 

BndBrd, Dil 

→

→

→

→

 Ref

; the CO

2

 mole

fraction in the sample air stream is then corrected to the water vapor mole
fraction that is in the reference air stream according to

C

C

w

w

s

wr

s

ws

ref

=

−

(

)

−

(

)

1

1000

1

1000

/

/

3-33

C

s

ws

 is the actual CO

2 

mole fraction in the sample cell diluted by w, and c

s

wr

is the equivalent sample cell CO

2

 mole fraction if it were diluted by w

ref.

It is important to distinguish the different water corrections that can be
applied in the LI-6262.  The Vapor Flag (FCT 76) can be in one of three
states:

0 - Corrections Off:

  No pressure broadening or dilution corrections are

applied.

1 - Band Broadening:

  A pressure broadening correction is applied, but no

dilution correction is performed.  The actual CO

2

 mole fraction in the sample

cell or the actual CO

2

 differential is displayed.

2 - BndBrd, Dil 

→

→

→

→

 Ref:

  Both a pressure broadening and a dilution

correction are applied.  The sample cell CO

2

 mole fraction and the CO

2

differential are corrected for differences in sample and reference air stream
water vapor contents.  This is the appropriate setting for photosynthesis
measurements.  

NOTE

:  This is the default setting when the system is

configured at the factory, or when the system is reset (FCT 08).

3.7  C

r

 is Unknown.  Measuring C

r 

against C

s

 = 0

Sometimes a CO

2

 differential must be measured when the reference CO

2

mole fraction is not precisely known.  For example, one might be measuring
photosynthesis in the field with ambient air as the reference gas, the exact
CO

2

 mole fraction of which is not known.  One could scrub the reference

cell and measure the incoming CO

2

 concentration in absolute mode.

However, there will be a small zero shift when the reference gas is reduced
from  around 350 ppm to 0 ppm, so a zero adjustment must be made each

Содержание li-6262

Страница 1: ...LI 6262 CO2 H2O Analyzer INSTRUCTION MANUAL ...

Страница 2: ...N CO2 ON OFF FUNCTION EEX ENTER 4 5 6 7 8 9 C 0 2 3 1 ZERO SPAN H2 O Publication Number 9003 59 March 1996 Software Version 2 02 LI COR inc P O Box 4425 4421 Superior Street Lincoln Nebraska 68504 Phone 402 467 3576 FAX 402 467 2819 Toll free 1 800 447 3576 U S Canada U S and Foreign Patents Pending ...

Страница 3: ...for a computing device However there is no guarantee that interference will not occur in a particular installation If this equipment does cause interference to radio or television reception that can be determined by turning the instrument off and on the user is encouraged to try to correct the interference by one or more of the following measures 1 Reorient the receiving antenna 2 Relocate the ins...

Страница 4: ...r language without prior written consent of LI COR Inc Copyright 1990 LI COR Inc ______________________________________________________________ IBM is a registered trademark of International Business Machines Corp PC TALK is a trademark of Freeware ProComm is a trademark of Data Storm Technologies Printing History New editions of this manual will incorporate all material since the previous edition...

Страница 5: ...Calculating Gas Concentration General 3 2 3 3 Calculating CO2 Concentration 3 6 3 4 Calculating H2O Concentration 3 6 3 5 Pressure Broadening Due to Water Vapor 3 8 3 6 Dilution Corrections 3 11 3 7 Cr is Unknown Measuring Cr Against Cs 0 3 12 Section IV Calibration 4 1 Calibration General Information 4 1 4 2 Differential Mode Calibration 4 2 4 3 Absolute Mode Calibration 4 5 4 4 H2O Absolute Mode...

Страница 6: ... 6 15 Section VII Maintenance 7 1 Recharging the 6000B and 6200B Batteries 7 1 7 2 Opening the LI 6262 7 1 7 3 Internal Soda Lime Desiccant 7 2 7 4 External Soda Lime Desiccant 7 4 7 5 Fan Filter 7 6 7 6 Fuses 7 6 Section VIII Troubleshooting APPENDIX A Specifications APPENDIX B List of Suppliers APPENDIX C Software Command Index APPENDIX D Channel Code Headers APPENDIX E LI 6262 Console Commands ...

Страница 7: ...e card for entering console commands via the LI 6262 keypad or from an external terminal Spare Parts Kit This kit contains replacement parts for your LI 6262 As you become familiar with the analyzer you will learn which items to keep close at hand and which items can be stored away External Scrubber and Desiccant Tube This tube is used during normal operation Several spare gaskets and adhesive dis...

Страница 8: ...provides 6 4 hours of battery life LI 6020 Battery Charger 92 138 184 276 VAC 47 to 63 Hz 1800 04 RS 232C Cable Used to connect the LI 6262 DCE to a standard IBM AT type 9 pin RS 232C communications port In addition LI COR manufactures a portable dew point generator LI 610 and a flow control unit LI 670 which are valuable accessories for calibrating and operating the LI 6262 LI 610 Portable Dew Po...

Страница 9: ...ide a zero gas source a span gas can be swapped between cells to adjust for any zero offset present during calibration The LI 670 also can be used as a power source for the LI 6262 a built in low battery detection circuit monitors battery life of the system Mounting brackets are included for attaching the LI 670 and LI 6262 making the system completely portable 1 2 Checking the Batteries If purcha...

Страница 10: ...ttach to the SCRUBBER holder on the back panel 3 Absolute or Differential mode operation The LI 6262 can be operated in absolute or differential mode In absolute mode the reference cell contains a zero concentration of CO2 and H2O The sample cell is connected to the unknown gas to be measured The signal from the sample cell is compared to the zero gas reference signal to provide absolute measureme...

Страница 11: ...he station barometric pressure Press FCT followed by 77 and enter the barometric pressure in kPa Pressure may also be input continuously using the 6262 03 Pressure Transducer from LI COR or through auxiliary channel 15 with an external pressure sensor as described in section 6 4 Set the parameters for RS 232C output if necessary Press FCT followed by 17 and enter the data output parameters Set the...

Страница 12: ...of battery leads with a 3 pin plug is included in your spare parts kit for connection to a user supplied battery 10 5 16VDC 1 5 amp maximum current required or other DC power supply If AC line voltage is being used make sure the AC VOLTAGE selector on the back panel is set correctly choose the 115 setting for 100 130VAC or the 220 setting for 200 260VAC and plug the line cord into the receptacle o...

Страница 13: ... operating the LI 6262 Insert filters into both the SAMPLE and REFERENCE airstreams before they enter the LI 6262 Failure to do this will lead to contamination of the sample and reference optical paths which can cause large zero offsets that may require expensive repairs The Gelman polypropylene filters included use PTFE filter elements with a 1 µm pore size They have excellent particle retention ...

Страница 14: ...mbers of IRG3 239 and below were shipped with internal Balston filters Balston filters have good particle retention with low flow resistance but they equilibrate slowly with changing humidities thus degrading the apparent response time and performance of the LI 6262 Replace the Balston filters with external Gelman filters as described above We recommend that the SAMPLE IN and REFERENCE IN ports be...

Страница 15: ...R fitting Attach the top hose nearest the perchlorate to the TO CHOPPER fitting Figure 2 1 Figure 2 1 Hose connections for operation in differential mode IMPORTANT Attach the hoses as shown in Figure 2 2 The hose nearest the soda lime is attached to the FROM CHOPPER fitting and the hose near the magnesium perchlorate is attached to the T O CHOPPER fitting This ensures that CO2 is purged first and ...

Страница 16: ...ry pump such as the 6262 04 must be used when operating in absolute mode See Section 4 4 for more information Orient the scrubber tube so that the soda lime is on the bottom and the magnesium perchlorate is on the top Attach the bottom hose nearest the soda lime to the FROM CHOPPER fitting An auxiliary pump should be placed between the FROM CHOPPER fitting and the bottom hose of the scrubber tube ...

Страница 17: ...Section 2 2 8 Setup Operation SAMPLE IN REFERENCE IN SAMPLE OUT REFERENCE OUT TO CHOPPER FROM CHOPPER Mg ClO4 2 SODA LIME PUMP Filter Figure 2 3 Hose connections for operation in absolute mode ...

Страница 18: ...ing Shutter Source Feedback Photodiode Lens Lens Dichroic Beam Splitter Thermoelectric Cooler Thermoelectric Cooler H2O Detector H2O Filter CO2 Detector CO2 Filter The infrared source is vacuum sealed for long life 10 000 hours and high stability A separate optical feedback circuit with a photodiode maintains the source at a constant color temperature 1250 K A gold reflector surrounding the IR sou...

Страница 19: ...e is focused through the gas cells and onto the detector by a lens at each end of the optical bench Focusing the radiation maximizes the amount of radiation that reaches the detector in order to provide maximum signal sensitivity All of these features provide a CO2 noise level that is typically 0 3 ppm peak to peak at 350 ppm when using 1 second signal averaging and 1 ppm peak to peak with 0 1 sec...

Страница 20: ...also write equation 3 2 as V K 1 τ 3 2b and V KA 3 2c The constant K is given on the calibration sheet Equation 3 2c indicates that the analyzer output voltage is proportional to absorptance however absorptance is a non linear function of CO2 mole fraction Absorptance and analyzer output voltage both increase with increasing CO2 mole fraction in the sample cell Figure 3 1 illustrates a typical rel...

Страница 21: ...libration temperature C or K The situation is a little more complicated in differential mode If we place a nonzero CO2 mole fraction in the reference cell then infrared radiation will be absorbed transmittance will decrease and νr should decline This decline is prevented however by an automatic gain control circuit that increases the detector gain by an amount necessary to hold νr constant This pr...

Страница 22: ... solve equation 3 4 for Vr giving V F C T T P P r r o o 1 3 5 Then rearrange equation 3 2b to find τr given Vr τr r V K 1 3 6 Equations 3 5 and 3 6 ordinarily apply to the situation where Cr is in the sample cell and zero is in the reference cell but if the cells are identical τr also computes the transmittance in the reference cell when Cr is present The gain correction G equals τr as shown earli...

Страница 23: ... The reference concentration value Cr µmol mol should be entered via FCT 59 If the reference air is not dry then cr should be the actual CO2 mole fraction in the presence of water vapor See sections 3 5 and 3 6 CO2 differential C µmol mol FCT 23 is C Cr CO2 partial pressure pc Pa displayed using FCT 24 is computed from C and total pressure P kPa by p cP c 1000 3 10 The CO2 weight fraction cg µg g ...

Страница 24: ...le fraction w and total pressure P kPa e wP 1000 3 15 The dewpoint temperature Td C FCT 38 is computed from an equation that was fit to the data of Goff and Gratch 1946 as given by List 1966 giving saturation vapor pressure as a function of temperature over a range of 50 to 50 C T z z d 242 62 7 6448 3 16 where e z log10 61083 and e is vapor pressure in kPa The LI 6262 computes the water vapor wei...

Страница 25: ...t broad band infrared absorption increases as pressure increases at constant absorber concentration Not all gases are equally effective in causing pressure induced line broadening Gases that are similar are more effective than dissimilar gases This effect is embodied in the concept of equivalent pressure or effective pressure Pe Total pressure P is equal to the sum of partial pressures of componen...

Страница 26: ...20 is entered into the LI 6262 using FCT 78 Equation 3 20 can be extended to include nitrogen as standard and both water vapor and oxygen or other gases as variable components Pe can be written in a more general form to anticipate that possibility Pe P 1 aw 1 Xw Σ bi 1 Xi 3 21 For the present equation 3 20 is implemented in the LI 6262 software equation 3 21 has not yet been tested Equation 3 20 c...

Страница 27: ...tion 3 25 into 3 23 and incorporating the constants L and R into a new function h gives A P h X T 3 26 In principle equation 3 26 can be solved for mole fraction giving X h A P T 1 3 27 Since LI COR gas analyzers produce an output voltage that is proportional to absorptance V KA 3 28 substituting 3 28 into 3 27 yields C F V P P T T o o 3 29 where C is the CO2 mole fraction in µmol mol 1 and the co...

Страница 28: ...gas analyzer and perhaps others as well 3 6 Dilution Corrections A dilution correction can be applied in the LI 6262 if desired When one component gas of multicomponent mixture is decreased at constant pressure the partial pressures of all other components are increased accordingly For example if water vapor is removed at constant pressure then the partial pressures of other components increase ac...

Страница 29: ...roadening or dilution corrections are applied 1 Band Broadening A pressure broadening correction is applied but no dilution correction is performed The actual CO2 mole fraction in the sample cell or the actual CO2 differential is displayed 2 BndBrd Dil Ref Both a pressure broadening and a dilution correction are applied The sample cell CO2 mole fraction and the CO2 differential are corrected for d...

Страница 30: ...l this avoids zero shifts and gain changes One can then measure the output voltage V and compute Vr and Cr according to equations 3 34 and 3 35 V V V K r 1 3 34 C F V P P T T r r o o 273 273 3 35 These values can be used as needed to compute Cs or C over as long a time period as Cr and temperature are stable Note This is not implemented in the instrument but is provided as an aid to those needing ...

Страница 31: ...l 52 p 95 2 Jamieson J A et al 1963 Infrared Physics and Engineering McGraw Hill New York N Y p 65 3 List R J 1966 Smithsonian Meteorological Tables 6th rev ed The Smithsonian Institution 527 pp 4 Wolfe W L and G J Zissis 1978 The Infrared Handbook Office of Naval Research Department of the Navy Washington D C ...

Страница 32: ...262 to LI COR for recalibration The user calibration consists of adjusting the zero and span potentiometers so that the analyzer s output matches the linearization polynomial F V This should be done on a daily basis unless the 6262 03 Pressure Transducer is installed as the span varies with barometric pressure and the zero varies with temperature Figure 4 1 illustrates the effects of the zero and ...

Страница 33: ...s for flow thru photosynthesis applications where drawdowns from ambient are expected There is generally a small zero shift when the reference concentration changes Therefore if operating in a mode in which there are significant changes in reference gas concentration you should re zero the analyzer following each change in concentration CO2 Zero and Span Calibration 1 Set the CO2 reference to zero...

Страница 34: ...r the LI 6262 requires that the reference cell water vapor mole fraction be entered as a parameter before differential measurements can be performed Therefore it will often be necessary to convert a dewpoint temperature into a vapor pressure and then into mole fraction Vapor pressure can be obtained from dewpoint temperature by making reference to Appendix F or by calculation Note that Appendix F ...

Страница 35: ...lute H2O concentration on the display reads zero 5 With a dry gas on the reference side flow a span gas through the sample cell Set the span potentiometer to read the value of the span gas in the appropriate units 6 Flow the span gas through both cells of the analyzer at the same flow rate Set the H2O reference FCT 68 to the value of the span gas in the appropriate units Display differential H2O F...

Страница 36: ... circuit A flow rate of approximately 500 ml per minute is sufficient to purge the reference cell The flow of dry air through the reference cell and scrubber tube assembly will also greatly affect the performance and maintenance requirements of the external soda lime magnesium perchlorate mixture An inherent property of soda lime is that a small amount of water vapor must be present for the chemic...

Страница 37: ...ion of LI 6262 with external pump for operation in H2O absolute mode Using the 6262 04 Reference Pump The 6262 04 pumps approximately 0 22 to 0 5 liters of air per minute which is sufficient to purge the reference cell The 6262 04 flow rate can be adjusted with the screwdriver included by turning the Flow Adjust potentiometer clockwise to increase the flow or counterclockwise to decrease the flow ...

Страница 38: ... Plug the battery cable from the 6262 04 into the battery jack on the analyzer 7 Attach the hoses Mg ClO4 2 REFERENCE IN fitting LI 6262 Soda Lime TO SCRUB fitting 6262 04 TO CHOPPER fitting LI 6262 REFERENCE OUT fitting LI 6262 This tube is threaded through the 6262 04 FROM CHOPPER fitting 6262 04 FROM CHOPPER fitting LI 6262 The finished assembly will look similar to that shown in Figure 4 3 bel...

Страница 39: ...Section 4 4 8 Calibration Figure 4 3 6262 04 Reference Pump installed on LI 6262 back panel ...

Страница 40: ...ir to the input of the analyzer and adjust the flow rate to be equal to the flow rate at which measurements will be taken 2 Monitor CO2 or H2O on the display and record the concentration after the reading has stabilized 3 Shut the flow off leaving this same concentration in the sample cell 4 Record the concentration from the display Correction factor Conc with flow Conc without flow When setting t...

Страница 41: ...ormally used in the calculation of CO2 concentration FCT 21 is transformed according to CO2 mVnew C2 Span mV C2 Zero The values of CO2 mVnew and H2O mVnew are used by the calibration polynomials to compute concentration but do not change the raw CO2 mV signal displayed at channel 21 or the raw H2O mV signal displayed at channel 31 or the output RS 232C values of either The values of H2 Zero and H2...

Страница 42: ...eas NOTE The LI 6262 will not accept remote commands while the Test Menu is active Exit the Test Menu and enter display mode the remote command will then be executed Absolute Mode Calibration 1 Set the CO2 zero Flow CO2 free air through the chopper housing reference and sample sides of the analyzer Send remote command 081 0 1 0 to set the zero 2 Set the CO2 span Let s assume that we are using a 50...

Страница 43: ...n describes how you can calibrate your LI 6262 using the LI 670 and a single span gas Absolute and Differential Mode Calibration with One Span Gas Absolute mode Set zero 1 Connect the LI 6262 Sample In fitting to the LI 670 Sample Out fitting and the LI 6262 Reference In fitting to the LI 670 Reference Out fitting 2 Enter the station barometric pressure into the LI 6262 at FCT 77 Alternatively you...

Страница 44: ... in absolute mode Differential mode operation requires three additional steps Differential mode Set zero 7 Perform steps 1 through 6 and then turn OFF the REFERENCE CO2 H2O Scrub switch Adjust the flow to near that which will be used during measurements 8 Adjust the LI 6262 to read zero when the displayed mole fraction is steady Only a small adjustment should be necessary about 5 ppm when switchin...

Страница 45: ...ng measurements by turning ON the Diff Zero switch and then using whichever scrubbers are needed CO2 H2O Scrub CO2 H2O Scrub Swap Diff Zero Aux Ports LI 670 Sample In Reference In Sample Ref Flow the span gas through both cells of the analyzer Many other calibration variations are possible For example you may want to recirculate air in a closed reference loop for absolute mode operation ...

Страница 46: ... Keypad Numeric keys 0 9 and decimal key Used to enter software function codes and calibration numbers Function key Function prompt is accessed allows user to enter any software function command 00 99 Exponent Scroll Up key Used to enter exponents i e when entering CO2 or H2O calibration numbers or to scroll upward through option lists Minus Scroll Down key Used to enter a negative number sign or ...

Страница 47: ...from 10 to 20 in the menu To illustrate the use of the FUNCTION key and the main menu try this 1 Press FCT 90 The display will show the main menu at 90 as DISP 2 Press to move down one entry to function 91 3 Press ENTER This will select function 91 which shows the channel code that is currently defined for the top line of display 1 and prompts for a new value 4 Press ENTER to retain the displayed ...

Страница 48: ...computer and LI 6262 for data transfer and for sending remote commands Look for the icon at left in the following section for examples of how to format entries to be sent to the LI 6262 5 3 Console Commands This section discusses each function in detail It may be helpful to reference the console command summary card while reading through the definitions of the following functions 00 Setup 00 SETUP...

Страница 49: ...erence mole fraction µmol mol and the choice of water correction depend upon your system setup See functions 59 and 76 for complete descriptions Check the calibration sheet to verify that the correct values are entered Prompt Description Related Function C2 T Calibration Temperature 51 C2 K Calibration Constant K 52 C2 A Calibration Coefficient A 53 C2 B Calibration Coefficient B 54 C2 C Calibrati...

Страница 50: ...ibration Temperature 61 H2 K Calibration Constant K 62 H2 A Calibration Coefficient A 63 H2 B Calibration Coefficient B 64 H2 C Calibration Coefficient C 65 H2 R H2O Reference mmol mol 68 02T K A B C REF 03 Set Miscellaneous Function 03 performs functions 71 75 and 77 Prompt Description Function P kPa Barometric Pressure 77 Avg s Signal Averaging Time 74 Aux A Auxiliary Input Coefficient A 71 Aux ...

Страница 51: ...w at initial power up or system reset Function Codes Display Top Bottom Lines Description 1 21 CO2 mV non linear 22 CO2 µmol mol absolute 2 23 CO2 µmol mol differential 29 CO2 µmol mol reference 3 41 Temperature mV 42 Temperature C 4 31 H2O mV non linear 32 H2O mmol mol absolute 5 33 H2O mmol mol differential 39 H2O mmol mol reference 6 43 Barometric Pressure kPa 44 Auxiliary mV Set the displays a...

Страница 52: ...1 Digital to Analog Conversions may be performed on channel codes 22 27 32 38 or 42 See function codes 80 83 for further details 05X low high where x is channel code 22 27 32 38 or 42 06 Set D A Conversion 2 Function 06 performs functions 84 85 and 86 DAC 2 Code NEW __ D A Conversion 2 same as 05 06X low high where x is channel code 22 27 32 38 or 42 ...

Страница 53: ...the menu 07Y Yes or 07N No 08 Test Menu DISPLAY Test Scrolls through display test menu While most of the items in the Test Menu are for technician use there are a few items of interest to many users The KBD Keyboard Test prompts to press any key each of the 16 keys should display correctly when pressed The D A Digital to Analog Test is used to test the digital to analog conversion capabilities of ...

Страница 54: ...K bytes of ROM program memory Geopotential Displays the geopotential height in feet or meters based on the current value of pressure at channel 43 This value can be provided by a sensor FCT 73 or as a keyboard entered constant FCT 77 Press the up or down arrow keys to toggle between units of feet and meters Geopotential height is height above sea level in a standard atmosphere The I O Input Output...

Страница 55: ...an change the configuration to that of a LI 6252 analyzer This function is primarily for factory use only so ordinarily this should not be changed Pressing 1 for Yes will remove all configuration parameters from the analyzer they will then need to be re entered Reset System 1 Yes 0 No YES or NO Clearing EEPROM SYSTEM TYPE LI 62X2 5 6 Enter 6 ...

Страница 56: ...ntegration Manual will cause the integration to continue until FCT is pressed or until a asterisk is received from the remote terminal Elaps tm elapsed time will cause the integration to run for the specified number of seconds Thrsh will cause the integration to continue until the target channel value drops below the threshold NOTE Pressing FCT or receipt of a remote command will always stop the i...

Страница 57: ...stant until the next integration is started X t xs ts t te xe Threshold value A t Σxi Non peak t t x x e s s e 2 Figure 5 2 Accumulating total area A and non peak area Channel 47 displays the peak value of the target channel during integration 09x start start value stop stop value x is channel code 22 29 or 32 39 to be integrated and denotes optional start and stop values The start value is requir...

Страница 58: ...and ending when it falls below 0 5 µmol mol 0932 1 1 Integrate channel 32 H2O mmol mol absolute starting immediately and ending when the next is received 0922 2 100 3 30 Integrate channel 22 CO2 µmol mol absolute starting when it goes above 100 µmol mol and ending 30 seconds later 10 Print Commands 10 PRINT Enters menu at command 10 ...

Страница 59: ...headers 11 12 Print Data Press FCT 12 to send a single line of data as defined in the Print List FCT 13 to the RS 232C port 12 13 Set Print List Print Col 1 0 NEW __ Scrolls through 10 print options Data from up to 10 channels may be sent to the RS 232C port at a specified interval see FCT 14 Enter up to 10 channel codes s 21 29 31 39 and 41 47 If all 10 print options are not needed press FCT to e...

Страница 60: ... the RS 232C port The interval can be 0 2 0 5 or any value from 1 to 3600 14x where x is any number 0 2 0 5 or 1 to 3600 15 Auto Header Auto Header 0 NEW __ Number of data lines between headers 1 999 The column header interval is the number of data lines which will be printed between column headers For example entering 5 will cause a column header to be printed after every 5 lines of data 15x wher...

Страница 61: ...arameters for H2O and CO2 The output should look similar to this CO2 T 3 5970E 01 K 1 7913E 04 A 1 4330E 01 B 9 5609E 06 C 7 8293E 09 D 1 1040E 12 E 7 5366E 17 Ref 0 0000E 00 Zero 0 0000E 00 Span 1 0000E 00 VC Corrections Off H2O T 4 1340E 01 K 1 5409E 04 A 6 3281E 03 B 3 1059E 06 C 1 1238E 12 Ref 0 0000E 00 Zero 0 0000E 00 Span 1 0000E 00 MISC AUX DEST 43 AUX A 5 9071E 01 AUX B 1 5360E 02 AUX C 0...

Страница 62: ...ollows See Section 6 for further details on data communications Baud rate 300 600 1200 2400 4800 or 9600 Data bits 7 or 8 Stop bits 1 or 2 Parity None Even or Odd Check DTR Data Terminal Ready Yes or No This is a hardware handshaking line The LI 6262 looks for DTR on pin 20 Check XON OFF Software Handshaking Yes or No Controls the flow of data between transmitting and receiving devices Receipt of ...

Страница 63: ...by entering the optional parameter For example entering 191 would send only the 01 CO2 Cal information and 1913 would send only the 13 RS 232C print list 19 will produce the entire list The entire list will appear something like this 01 3 5970E 01 1 7913E 04 1 4330E 01 9 5609E 06 7 8293E 09 1 1040E 12 7 5366E 17 0 0000E 00 0 02 4 1340E 01 1 5409E 04 6 3281E 03 3 1059E 06 1 1238E 12 0 0000E 00 0 00...

Страница 64: ...m Software 5 19 74 1 75 0 0000E 00 76 0 77 9 6805E 01 78 1 5000E 00 91 21 31 92 23 29 93 41 42 94 31 32 95 33 39 96 43 44 97 0 0 98 0 0 99 0 0 19 n n is optional parameter for selecting just one output channel code ...

Страница 65: ...e viewed by pressing FCT they are not executable from the main menu NOTE CO2 reference value may be entered via the keyboard as a constant FCT 59 or entered via analog signal See Section 6 4 Code Description 21 CO2 mV non linear 22 CO2 µmol mol absolute 23 CO2 µmol mol differential 24 CO2 Pa absolute 25 CO2 Pa differential 26 CO2 µg g absolute 27 CO2 µg g differential 29 CO2 µmol mol reference ...

Страница 66: ...by pressing FCT they are not executable from the main menu Code Description 31 H2O mV non linear 32 H2O mmol mol absolute 33 H2O mmol mol differential 34 H2O kPa absolute 35 H2O kPa differential 36 H2O mg g absolute 37 H2O mg g differential 38 H2O Dewpoint 39 H2O mmol mol reference NOTE H2O reference value may be entered via the keyboard as a constant FCT 68 or entered via analog signal see Sectio...

Страница 67: ...4 Auxiliary mV NOTE Pressure kPa FCT 43 is used for computations This comes from FCT 77 or an analog signal at FCT 44 see Section 6 4 45 Timer Timer 3 7 Displays accumulated time in seconds from instrument start up The Timer acts as a counter which accumulates the number of seconds since instrument start up to 999 999 or since the Reset Timer function FCT 18 was last executed The Timer can also be...

Страница 68: ...he last integration or the accumulating area during the present integration 46 47 Integration Peak Value Displays the peak value of the target channel obtained during the last integration or the largest value so far during the present integration 47 49 Software Revision I D Rev ID 2 02 Software revision number Press FCT to escape 49 ...

Страница 69: ...ation Temperature 52 C2 K Calibration Constant K 53 C2 A Calibration Coefficient A 54 C2 B Calibration Coefficient B 55 C2 C Calibration Coefficient C 56 C2 D Calibration Coefficient D 57 C2 E Calibration Coefficient E 59 C2 R CO2 Reference µmol mol The CO2 reference value FCT 59 should reflect the dilution by water vapor if the reference is not dry For example if the reference gas contains 300 µm...

Страница 70: ... individual H2O calibration coefficients as well as the prompt to enter the H2O reference FCT 68 H2 R 0 NEW __ Enter H2O reference in mmol mol Code Prompt Description 61 H2 T Calibration Temperature 62 H2 K Calibration Constant K 63 H2 A Calibration Coefficient A 64 H2 B Calibration Coefficient B 65 H2 C Calibration Coefficient C 68 H2 R H2O Reference mmol mol ...

Страница 71: ... channel 15 on the back panel terminal strip The input signal is transformed by Y A Bx Cx2 where x is the signal in mV and the coefficients A B and C are entered in FCTs 71 72 and 75 The value Y can be treated as pressure FCT 43 reference CO2 FCT 29 or reference H2O FCT 39 according to FCT 73 71 Auxiliary A Offset Aux A 0 0 NEW __ Auxiliary A Offset value 71 A ...

Страница 72: ... input may be sent to channel codes 29 CO2 reference 39 H2O reference or 43 pressure Entering any other code at the NEW prompt sets the destination to 0 and deactivates the input channel Setting this destination to 29 39 or 43 causes the values of FCT 59 68 or 77 respectively to be ignored 73X where x is the destination channel 29 39 43 or null 75 Auxiliary C Aux C 0 0 NEW __ Auxiliary C value 75 ...

Страница 73: ... signal This results in a significant decrease in the apparent noise level but slows the response time as well This average time affects all computed values of CO2 FCTs 22 to 27 and H2O FCTs 32 38 whether displayed or output to a DAC channel or output by RS 232C It does not affect the raw mV signals on the back terminal strip Setting Average Time to zero will turn off all digital averaging and the...

Страница 74: ... System Reset FCT 08 is performed See Sections 3 4 and 3 5 for complete explanations of the vapor corrections Corrections Off No vapor corrections performed State 0 Band Broadening Correct for band broadening State 1 BandBrd Dil REF Band broadening dilution corrections applied State 2 76X where x is 0 1 or 2 for no correction correct for band broadening or correct for band broadening and dilution ...

Страница 75: ...tinuously using the 6262 03 Pressure Transducer from LI COR or through connector 15 on the back panel terminal strip as described in section 6 4 77X where x is the barometric pressure in kPa 78 Vapor Correction a VpCrr A 1 5 NEW __ Vapor correction value a Vapor correction coefficient a is factory entered a 1 5 See Section 3 5 for a description of the vapor correction This value is only used when ...

Страница 76: ... the LI 6262 back panel terminal strip 0 5V 0 100 mV and 4 to 20mA To convert voltage output V to the value X that is driving it X X X R V X F o o where R full scale voltage range 5V or 100mV XF the value of X corresponding to full scale voltage set in FCT 83 or 86 and Xo the value of X corresponding to zero volts set in FCT 82 or 85 For current I X X X I X X F o o F 16 5 4 where XF is the value o...

Страница 77: ...mited voltage range some resolution may be lost due to signal noise considerations when using the smaller output range The output impedance of the 0 100 mV range is 50 100Ω so a measuring or logging device with a high input impedance should be used Note that resolution is maximized by minimizing the range to be covered For example if you are making CO2 measurements that are always less than 400 pp...

Страница 78: ...n 1 Enter channel code 22 27 32 38 or 42 as the channel to output through analog output channel 1 82 D A Conversion 1 Minimum 1 0V NEW __ Digital channel value which corresponds to 0V or 4mA on DAC 1 83 D A Conversion 1 Maximum 1 5V NEW __ Digital channel value which corresponds to full scale 5V 100mV or 20mA on DAC 1 ...

Страница 79: ... Code NEW __ D A Conversion 2 same as 81 85 D A Conversion 2 Minimum 2 0V NEW __ Digital channel value which corresponds to 0V or 4mA on DAC 2 86 D A Conversion 2 Maximum 2 5V NEW __ Digital channel value which corresponds to full scale 5V 100mV or 20mA on DAC 2 ...

Страница 80: ...essing the 1 key 92 defines display 2 etc Displayable quantities are 21 29 31 39 or 41 45 All displays can be defined in one operation at FCT 04 or they can be defined individually using FCT 91 99 as shown below 1 Top New __ Channel code for top of display 1 1 Bottom NEW __ Channel code for bottom of display 1 91x x 92x x 93x x etc where x is any channel code 21 27 29 31 39 and 41 47 ...

Страница 81: ...n be set in the LI 6262 software FCT 17 Baud Rate 300 600 1200 2400 4800 or 9600 Data Bits 7 or 8 Stop Bits 1 or 2 Parity Odd Even or None Check DTR Yes No Check XON XOFF Yes No Analog Output Two linear voltage output channels are provided which have 0 100mV or 0 5V ranges The signals for these channels can be scaled over any concentration range in any units see Section 5 3 FCT 80 The linear chann...

Страница 82: ...he female 25 pin D connector on the back panel labeled RS 232C DCE The LI 6262 is configured as Data Communications Equipment DCE which means that it can communicate directly with computers RS 232C printers and other devices configured as Data Terminal Equipment DTE using only a cable that has pin for pin connections between the connectors on each end The LI COR 1000 04 RS 232C cable will work wit...

Страница 83: ...e 1000 90 software described in the following section Connect the appropriate cable 2 To test the cable connections and make sure that the computer software is configured properly press FCT 16 which will print a list of the current calibration data for the LI 6262 If nothing is sent make sure that the cable connections are correct and consult the software manual for the software you are using 3 Pr...

Страница 84: ...ON or OFF Toggles between ON and OFF Having the echo ON is useful to view the characters on the CRT which are typed if a computer is used to backload remote commands to the LI 6262 F6 File Specifies the file into which incoming data will be copied if desired Specify both the filename and the path where you want to copy the data file For example typing C DATA will create an ASCII file named DATA on...

Страница 85: ...nel edited If more than one argument is required the first follows the channel identifier without a space or comma and subsequent arguments if any are separated by commas only For example typing 1321 32 33 38 41 will change the print list which is output to your terminal to channel codes 21 32 33 38 and 41 Uploading ASCII Files to the LI 6262 Remote commands can be written in an ASCII file and cop...

Страница 86: ...Using an Apple Macintosh Sending data to the Macintosh requires a Hayes compatible modem cable for the Macintosh Most Hayes modem cables terminate with a male 25 pin D connector that will plug directly into the LI 6262 In the event that your cable has the wrong gender use a female to female gender changer with pin for pin connections A number of data transfer software programs are commercially ava...

Страница 87: ...splayed This can happen at lower baud rates or if the handshaking XON XOFF or DTR is preventing the data from being sent 6 3 Analog Output Analyzer output can be recorded by connecting a logging device to the terminal strip on the back of the analyzer Both linear outputs scaled over any range and in any units and non linear outputs are available Measuring Linear Analyzer Output The LI 6262 has two...

Страница 88: ...ero volts corresponds to 0 µmol mole 1 5V 100 XF full scale corresponds to 100 µmol mole When a voltage range R is selected the DAC output voltage V resulting from a CO2 differential X is given by V R X X X X o F o where R 5V or 100mV If the 4 to 20mA current loop is selected the output current I milliamps is I X X X X o F o 16 To convert the DAC voltage output signal to µmol mol or other units X ...

Страница 89: ... for any variable is X 2 11 XF Xo 4 88 x 10 4 XF Xo voltage and X 2 12 XF Xo 2 44 x 10 4 XF Xo current As an example if XF 1000 and Xo 0 the resolution will be about 0 5 µmol mol on either voltage channel and 0 25 µmol mol on the current channel Timing The DAC outputs change whenever the target channel changes All of the CO2 values FCTs 22 27 are computed at 5 Hz The H2O values FCTs 32 38 however ...

Страница 90: ... or DAC1 100mV The negative input should be connected to the terminal labeled SIG GND Connect another input from the data logger to the terminal labeled DAC2 5V or DAC2 100mV to measure the linear output of channel 2 DAC1 5V DAC1 100mV DAC1 20mA DAC2 5V DAC2 100mV DAC2 20mA SIG GND SIG GND CO2 0 1S CO2 1S H2O 0 1S H2O 1S SIG GND TEMP 5V AUX CHASSIS GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 DATA L...

Страница 91: ...er to the terminal labeled DAC1 20mA for channel one or DAC2 20mA for channel two Connect the negative input to one of the terminals labeled SIG GND DAC1 5V DAC1 100mV DAC1 20mA DAC2 5V DAC2 100mV DAC2 20mA SIG GND SIG GND CO2 0 1S CO2 1S H2O 0 1S H2O 1S SIG GND TEMP 5V AUX CHASSIS GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 DATA LOGGER Figure 6 2 Connection of data logger for current loop output ...

Страница 92: ... terminal To measure analyzer temperature or the voltage output with a different response time connect the appropriately labeled terminal to the positive input of another channel on the data logger The resolution which the data acquisition device should have is dependent upon the noise level of the analyzer 0 2 µmol mol C02 typical 0 4 µmol mol maximum or 0 05 mmol mol H2O typical 0 2 mmol mol max...

Страница 93: ...Transducer is installed in your analyzer the auxiliary channel input is no longer available the raw mV reading from the transducer can be measured at this terminal however Please see Section 6 6 for a complete discussion of the 6262 03 Connect the positive input from the sensor to the terminal labeled AUX Connect the negative input to the terminal labeled SIG GND The auxiliary channel has an input...

Страница 94: ...nnect the positive lead from the data logger to the terminal labeled TEMP 5V and the negative lead to the terminal labeled SIG GND Fig 6 5 Temperature output is linear and can be computed according to T C C V 50 4096 mV where V the analyzer output in millivolts and 0V 0 C DAC1 5V DAC1 100mV DAC1 20mA DAC2 5V DAC2 100mV DAC2 20mA SIG GND SIG GND CO2 0 1S CO2 1S H2O 0 1S H2O 1S SIG GND TEMP 5V AUX C...

Страница 95: ...terminal on the terminal strip the signal can be measured by connecting a voltmeter or datalogger to the Aux and Sig Gnd terminals Pressure can then be calculated externally if desired Internal computations are performed provided FCTs 71 72 73 and 75 are set correctly see Software Considerations below Digital Board Adapter Board Power Supply Pressure Transducer Terminal Strip AUX INPUT terminal 15...

Страница 96: ...e slope of the line representing the sensor s response Figure 6 7 On the 6262 03 calibration sheet the offset A is given as FCT 71 and the multiplier B is given as FCT 72 Enter these values into the software at FCT 71 Aux A and FCT 72 Aux B Make sure that FCT 75 Aux C is set to zero These values convert the mV output of the pressure transducer to pressure in units of kPa Y 0 A X Slope B Figure 6 7...

Страница 97: ...0 Aux A 0 0 NEW 58 239 Aux B 0 0 NEW 0 01510 FCT 72 FCT 73 FCT 75 FCT 71 You can view the pressure value at FCT 43 and mV output at FCT 44 Both of these values can be viewed on a custom display or sent via the RS 232C output to a printer and or computer terminal ...

Страница 98: ...results charge the batteries overnight Batteries may also be charged during operation of the LI 6262 with AC power Charging times will be longer than those given above however At room temperature the 6000B will run the LI 6262 for approximately 3 2 hours and the 6200B will last about 6 4 hours NOTE One set of external leads with a 3 pin plug connection is also included in the spare parts kit for i...

Страница 99: ...ts purpose is to keep the detectors free of CO2 and water vapor and their dewpoints below 5 C If the CO2 H2O concentration in the detectors rises the analyzer response curves will change and the calibration polynomials will no longer match the response curves and the factory supplied calibration functions will be invalid If the dewpoint in the detectors rises above 5 C condensation may form result...

Страница 100: ...3 Remove the old bottle insert the new bottle into the bottle cover bottom first and reattach the cover to the analyzer Note that there is a small wad of polyester fiber in the bottom of the nickel plated bottle cover to prevent the soda lime desiccant bottle from rattling New bottle Hole in cap Nickel plated bottle cover Polyester fiber WARNING Magnesium perchlorate is the recommended desiccant s...

Страница 101: ...move In differential mode with the scrubber tube connected to the chopper ports the soda lime desiccant will need to be changed every 1 4 weeks depending on usage Once the scrubber tube removes the initial CO2 and water vapor from the circuit it will only need to remove the small amounts of CO2 and water vapor resulting from tiny leaks and diffusion into the system In absolute mode the soda lime d...

Страница 102: ...e that the filter paper discs on either end cap are not clogged reduces flow rate or torn Adhesive ringed replacement discs are included in the spare parts kit LI COR part 9960 040 Magnesium perchlorate cannot be regenerated after use Dispose of properly To chopper From chopper Soda Lime Fiberglass Wool Magnesium Perchlorate Figure 7 2 External soda lime desiccant tube assembly ...

Страница 103: ...59 7 6 Fuses There are two fuse holders on the back panel The 1 2 amp slow blow fuse is for 110 VAC line voltage and the 1 4 amp slow blow fuse is for 220 VAC line voltage The 2 amp fast blow fuse is for the external batteries If the LI 6262 fails to turn on check the fuse for the power source you are using battery or AC If the analyzer continually blows fuses it is in need of repair NOTE At 50 Hz...

Страница 104: ... set properly Check the fuses to see if one has blown Display flickers then goes out The analyzer is probably shutting down because the battery voltage is too low 10 5 V Try another battery Ready Light Won t Illuminate The ready light may fail to illuminate for a number of reasons some of these problems you can fix yourself Ambient temperature is greater than about 55 C CO2 level in the reference ...

Страница 105: ...ir through the sample cell and breath into the cool air intake filter just below the RS 232C port at the back of the analyzer The displayed CO2 should not rise by more than a few ppm A sharp rise in the displayed CO2 coinciding with your breathing indicates a leak A slow increase of 2 to 3 ppm depending on the flow rate of air through the sample cell can be expected due to diffusion of CO2 through...

Страница 106: ... 5 minutes Gas Temperature Measured by a thermistor Accuracy 0 5 C 0 60 C Resolution 0 01 C Gas Pressure Maximum allowable pressure is 17 kPa Maximum Flow through Analyzer 10 liters minute Software Features Setup of parameters scaling of analog outputs signal averaging time selection of RS 232C output parameters selection of automatic output of data external control of software via the RS 232C por...

Страница 107: ...ypical 0 002 kPa at 2 kPa with 1 second response time 0 006 kPa at 2 kPa with 0 1 second response time Noise Level dewpoint peak to peak Typical 0 02 C at 2 kPa with 1 second response time 0 06 C at 2 kPa with 0 1 second response time CO2 Analyzer Specifications Range 0 3000 ppm Accuracy 1 ppm at 350 ppm 3 ppm maximum 2 ppm at 1000 ppm 6 ppm maximum Zero Drift over time First Hour 5 ppm at 25 C Af...

Страница 108: ...e Transducer Specifications Pressure Range 0 to 115 kPa absolute Accuracy with software correction 0 1 full scale Resolution 0 002 kPa Signal noise peak to peak 0 002 kPa typical Power consumption 50 mA steady state Weight 0 88 oz 25 g ...

Страница 109: ...Chemicals P O Box 245 Powell OH 43065 Phone 614 881 5501 FAX 614 881 5989 Toll free 800 858 9682 Soda Lime Part 66352 Mg ClO4 2 Part 49001 500g 8 water Fisher Scientific 711 Forbes Avenue Pittsburgh PA 15219 4785 Phone 201 467 6400 FAX 201 379 7415 Toll free 800 776 7000 Toll free FAX 800 926 1166 Soda Lime Part S201 212 LI COR Part 9960 071 Mg ClO4 2 Part M54 500 500g Thomas Scientific P O Box 99...

Страница 110: ...6 Set D A Conversion 2 5 7 07 Backlight ON OFF 5 8 08 Test Menu 5 8 09 Integrate 5 11 10 PRINT 5 13 11 Print Header 5 14 12 Print Data 5 14 13 Set Print List 5 14 14 Auto Print 5 15 15 Auto Header 5 15 16 Print Calibration Data 5 16 17 Set RS 232C Port 5 17 18 Reset Timer 5 18 19 Full Status 5 18 20 CO2 5 20 21 CO2 raw mV 5 20 22 CO2 µmol mol absolute 5 20 23 CO2 µmol mol differential 5 20 24 CO2 ...

Страница 111: ...re C 5 22 43 Pressure kPa 5 22 44 Auxiliary mV 5 22 45 Timer 5 22 46 Integration A 5 23 47 Integration peak value 5 23 49 Software Revision I D 5 23 50 CO2 CALIBRATION 5 24 51 CO2 Calibration T 5 24 52 CO2 Calibration K 5 24 53 CO2 Calibration A 5 24 54 CO2 Calibration B 5 24 55 CO2 Calibration C 5 24 56 CO2 Calibration D 5 24 57 CO2 Calibration E 5 24 59 CO2 Reference µmol mol 5 24 60 H2O CALIBRA...

Страница 112: ... 74 Average Time 5 28 75 Auxiliary C 5 27 76 Vapor Flag 5 29 77 Pressure 5 30 78 Vapor Correction a 5 30 80 DAC 5 31 81 D A Conversion Code 1 5 33 82 D A Conversion Code 1 Min 5 33 83 D A Conversion Code 1 Max 5 33 84 D A Conversion Code 2 5 34 85 D A Conversion Code 2 Min 5 34 86 D A Conversion Code 2 Max 5 34 90 DISPLAYS 5 35 91 99 Displays 1 9 5 35 ...

Страница 113: ...ol mol absolute 22 C2µm m CO2 µmol mol differential 23 C2 Pa CO2 Pa absolute 24 C2 Pa CO2 Pa differential 25 C2 µg g CO2 µg g absolute 26 C2µg g CO2 µg g differential 27 REFµm m CO2 reference µmol mol 29 H2 mV H2O raw mV 31 H2 mm m H2O mmol mol absolute 32 H2mm m H2O mmol mol differential 33 H2 kPa H2O kPa absolute 34 H2 kPa H2O kPa differential 35 H2 mg g H2O mg g absolute 36 H2 mg g H2O mg g dif...

Страница 114: ...a 13 Set Print List 14 Auto Print 15 Auto Header 16 Print Calibration Data 17 Set RS 232C Port 18 Reset Timer 19 Full Status Channel Codes 20 CO2 21 CO2 raw mV 22 CO2 µmol mol abs 23 CO2 µmol mol diff 24 CO2 Pa abs 25 CO2 Pa diff 26 CO2 µg g abs 27 CO2 µg g diff 29 CO2 µmol mol ref 30 H2O 31 H2O raw mV 32 H2O mmol mol abs 33 H2O mmol mol diff 34 H2O kPa abs 35 H2O kPa diff 36 H2O mg g abs 37 H2O m...

Страница 115: ...Calibration A 64 H2O Calibration B 65 H2O Calibration C 68 H2O reference mmol mol Calibration and Configuration Stacks 70 MISC 71 Auxiliary A 72 Auxiliary B 73 Auxiliary Destination 74 Average Time 75 Auxiliary C 76 Vapor Flag 77 Pressure 78 Vapor Correction a 80 DAC 81 D A Conv Code 1 82 D A Conv 1 Min 83 D A Conv 1 Max 84 D A Conv Code 2 85 D A Conve 2 Min 86 D A Conv 2 Max 90 DISP 91 Display 1 ...

Страница 116: ... low high same as 05 07Y Yes or 07N No to turn backlight ON OFF 09x start start value stop stop value x is channel code 22 29 32 39 11 prints header 12 prints data 13x x x x x x x x x x x is any channel code 21 29 31 39 41 47 14x prints a line of data every x seconds where x is any number 0 2 0 5 or 1 to 3600 15x prints a column header every x lines of data from 1 to 999 16 prints calibration stac...

Страница 117: ... 29 52 29 69 24 29 87 30 06 30 23 30 42 30 60 30 78 30 97 31 15 31 34 31 53 25 31 72 31 91 32 10 32 29 32 49 32 68 32 87 33 06 33 26 33 46 26 33 66 33 86 34 07 34 26 34 47 34 67 34 88 35 08 35 29 35 49 27 35 77 35 92 36 12 36 34 36 55 36 77 36 99 37 20 37 42 37 64 28 37 86 38 08 38 30 38 52 38 76 38 98 39 20 39 44 39 66 39 90 29 40 13 40 36 40 59 40 83 41 07 41 30 41 54 41 78 42 02 42 27 30 42 50 ...

Страница 118: ...ed data 4 Request to Send 5 Clear to Send 6 Data Set Ready 7 Signal Ground 8 Carrier Detect 9 19 Not connected 20 Data Terminal Ready 21 25 Not connected 1000 04 DTE To DCE Cable The 1000 04 cable included is a pin for pin connection between the 25 pin connectors on either end The 1000 04 is terminated with male connectors on both ends a female to female gender changer may be required to connect t...

Страница 119: ...pm double mV double Cr double Tirga double vp_r double vp_s double kPa static double cal double mv static double temp_correction double t static double inverse_cal double cppm static double cal_slope double mv static double chi double mfw static double p0_over_p double kPa static double T_cal K_cal A_cal B_cal C_cal D_cal E_cal Water_A static int water_flag static double ppm double mV double Cr do...

Страница 120: ...chi_ws chi vp_s kPa eff_mv mV chi_ws p0_over_p kPa result chi_ws cal eff_mv tc return result differential mode chi_wr chi vp_r kPa eff_cr Cr temp_correction Tirga chi_wr inv_cal inverse_cal eff_cr Vref chi_wr inv_cal p0_over_p kPa gain 1 0 Vref K_cal return ppm Vref mV gain 0 Tirga 0 vp_s kPa static double cal double mv The basic irga cal equation polynomial double rtn rtn A_cal B_cal C_cal D_cal ...

Страница 121: ...mode with cppm in the sample cell double mv_old 0 mv c crude first guess if water_flag mv cppm 75 5000 else mv cppm 3000 5000 while fabs mv mv_old 0 5 mv_old mv c cal mv_old mv mv_old c cppm cal_slope mv_old return mv static double cal_slope double mv returns the slope of the cal function return A_cal 2 B_cal 3 C_cal 4 D_cal 5 E_cal mv mv mv mv static double chi double mfw ...

Страница 122: ...ref double vap_samp double water_corr_a int vapor_correct_flag Compute co2 concentration umol mol Cal_temp calibration temp C Cal_k calibration K factor coeffs Calibration A B C D and E mv raw CO2 signal mV temp IRGA temp C ref Co2 reference concentration umol mol vap_ref Vapor concentration mmol mol of reference side vap_samp Vapor concentration umol mol of sample side water_corr_a A value for wa...

Страница 123: ... It says what the concentration in the sample cell would be if the water vapor concentration there were the same as in the reference cell if vapor_correct_flag 2 Cs 1 0 vap_ref 1000 0 1 0 vap_samp 1000 0 return Cs double compute_h2o double Cal_temp double Cal_k double coeffs double mv double temp double ref double pressure Compute co2 concentration umol mol Cal_temp calibration temp C Cal_k calibr...

Страница 124: ...on in mmol mol double Ws water_flag 1 T_cal Cal_temp K_cal Cal_k A_cal coeffs 0 B_cal coeffs 1 C_cal coeffs 2 D_cal 0 E_cal 0 Ws ppm mv ref temp 0 0 pressure return Ws double dewpoint double vp_kPa double z z log10 vp_kPa 61083 return 242 62 z 7 6448 z ...

Страница 125: ...ps or delivers the instrument to LI COR inc at LI COR inc s factory in Lincoln Nebraska U S A within 30 days after LI COR inc has received written notice of the defect Unless other arrangements have been made in writing transportation to LI COR inc by air unless otherwise authorized by LI COR inc is at customer expense 5 No charge repair parts may be sent at LI COR inc s sole discretion to the pur...

Страница 126: ...he date the instrument is shipped to a user who is a customer or eighteen months from the date of shipment to LI COR inc s authorized distributor whichever is earlier This warranty supersedes all warranties for products purchased prior to June 1 1984 unless this warranty is later superseded DISTRIBUTOR or the DISTRIBUTOR S customers may ship the instruments directly to LI COR if they are unable to...

Страница 127: ... LI COR inc 4421 Superior Street P O Box 4425 Lincoln Nebraska 68504 USA Phone 402 467 3576 FAX 402 467 2819 Toll free 1 800 447 3576 U S Canada E mail envsales env licor com Internet http www licor com ...

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