Troubleshooting
Soil Chamber Problems
Using the LI-6400
20-39
tor), put a pencil mark on the outside of the two halves so that it can be
reassembled correctly.
Soil Chamber Problems
Pump DoesnÕt Run
When configured for the 6400-09 Soil Flux Chamber, the pump turns on and
off automatically during the measurement cycles. If the sample cell CO
2
con-
centration is above the lower window value (target - delta), then pump should
come on when you start a measurement until
CO2S_µml
falls below that val-
ue. When
CO2S_µml
rises above the upper window value ( delta), the
pump should turn back on, unless the number of requested cycles has been
completed. If this is not happening, it could be for the following reasons:
1
OPEN 3.01 and no CO
2
mixer installed
There is a bug in OPEN 3.01 that affects units configured for soil flux mea-
surements that do not have a CO
2
mixer installed. Either upgrade to OPEN
3.2, or else do the following: 1) Press
K
in OPENÕs main screen, 2) At the ok
prompt, type
4000 nullonflow
and press
enter
, 3) Press
escape
to return to
the main screen.
2
Check the auxiliary operating parameters
There are 4 parameters (3 in OPEN 3.01) accessible in
f2
level 3
(
AUX OP Params
), that influence the pumpÕs behavior.
ÒExtra Draw Down
(ppm)Ó
can be used to intentionally overshoot the lower limit, providing extra
time for things to stabilize before the next measurement cycle.
ÒDead Time
(secs)Ó
prevents measurements from starting too soon after the pump turns
off.
ÒMin Measure Time (secs)Ó
is the minimum measurements time, and
prevents the pump from turning on again too soon.
ÒFlow during DrawDownÓ
(in version 3.2) lets you set the approximate flow rate when the pump is on.
75%
25%
Figure 20-11. Schematic representation of the LI-6400Õs flow divider,
that partitions flow to the sample and reference cells of the IRGA.
Summary of Contents for LI-6400
Page 1: ...Using the LI 6400 Portable Photosynthesis System ...
Page 15: ...Part I The Basics ...
Page 16: ......
Page 174: ...Making Measurements Answers to Questions 4 56 Using the LI 6400 4 ...
Page 175: ...Part II Useful Details ...
Page 176: ......
Page 200: ...Standard Tools Power ON Hooks 5 24 Using the LI 6400 5 ...
Page 214: ...Real Time Data Real Time Graphics 6 14 Using the LI 6400 6 ...
Page 234: ...Environmental Control Light Control 7 20 Using the LI 6400 7 ...
Page 244: ...Light Sensor Considerations Gallium Arsenide Phosphide GaAsP Sensor 8 10 Using the LI 6400 8 ...
Page 288: ...Data Logging Making Your Own AutoPrograms 9 44 Using the LI 6400 9 ...
Page 289: ...Part III Working With Files ...
Page 290: ......
Page 312: ...The LPL File System Troubleshooting 10 22 Using the LI 6400 10 ...
Page 340: ...Downloading Files Using a Data Capture Program 11 28 Using the LI 6400 11 ...
Page 375: ...Part IV Configuration Issues ...
Page 376: ......
Page 420: ...Defining User Variables Old Style vs New Style 15 18 Using the LI 6400 15 ...
Page 454: ...Using an Energy Balance Further Reading 17 12 Using the LI 6400 17 ...
Page 455: ...Part V Maintenance Troubleshooting ...
Page 456: ......
Page 572: ...Troubleshooting Useful Information 20 46 Using the LI 6400 20 ...
Page 593: ...Part VI Programming ...
Page 594: ......
Page 622: ...Programming with LPL Compiler Directives 22 28 Using the LI 6400 22 ...
Page 846: ...Index I 16 Using the LI 6400 ...