Light Sensor Considerations
Specifying the Source and Sensor
Using the LI-6400
8-3
There is a third type of light sensor that is used in the LI-6400. It is a silicon
diode that monitors and controls the optional 6400-02 or -02B LED Light
Source. The silicon diode light sensor has a wide response that covers the red
and blue LED emission range. It is also an unfiltered sensor, but calibration
is simplified because it only views radiation from the LED light source. A cal-
ibration coefficient is provided with each 6400-02 or -02B LED Light Source.
Specifying the Source and Sensor
One of the configuration parameters of OPEN involves specifying the light
source (and indirectly, the sensor). There are reasons this information needs
to be known
¥
LED Light Source Control
Is a light source installed? The answer to this question determines whether or
not the lamp control key in New Measurements mode is active. It also tells
the software what type of in-chamber light sensor is connected.
¥
Calibration Issues
Whatever the type of light sensor being used, it has a calibration factor which
converts raw mV to µmol m
-2
s
-1
photon flux. This conversion factor depends
on the spectral characteristics of the incident radiation. The software can ad-
just this factor depending on what the light source is.
¥
Energy Balance Issues
When leaf temperature is not directly measured, it is computed using a leaf
energy balance (described in Chapter 17). One of the inputs of this computa-
tion is the absorbed radiant energy by the leaf, and this again depends on the
spectral characteristics of the incident radiation.
Calibration Equations
The equations that OPEN uses for computing the readings of its light sensors
are (14-14) through (14-16), starting on page 14-8.
Содержание LI-6400
Страница 1: ...Using the LI 6400 Portable Photosynthesis System ...
Страница 15: ...Part I The Basics ...
Страница 16: ......
Страница 174: ...Making Measurements Answers to Questions 4 56 Using the LI 6400 4 ...
Страница 175: ...Part II Useful Details ...
Страница 176: ......
Страница 200: ...Standard Tools Power ON Hooks 5 24 Using the LI 6400 5 ...
Страница 214: ...Real Time Data Real Time Graphics 6 14 Using the LI 6400 6 ...
Страница 234: ...Environmental Control Light Control 7 20 Using the LI 6400 7 ...
Страница 244: ...Light Sensor Considerations Gallium Arsenide Phosphide GaAsP Sensor 8 10 Using the LI 6400 8 ...
Страница 288: ...Data Logging Making Your Own AutoPrograms 9 44 Using the LI 6400 9 ...
Страница 289: ...Part III Working With Files ...
Страница 290: ......
Страница 312: ...The LPL File System Troubleshooting 10 22 Using the LI 6400 10 ...
Страница 340: ...Downloading Files Using a Data Capture Program 11 28 Using the LI 6400 11 ...
Страница 375: ...Part IV Configuration Issues ...
Страница 376: ......
Страница 420: ...Defining User Variables Old Style vs New Style 15 18 Using the LI 6400 15 ...
Страница 454: ...Using an Energy Balance Further Reading 17 12 Using the LI 6400 17 ...
Страница 455: ...Part V Maintenance Troubleshooting ...
Страница 456: ......
Страница 572: ...Troubleshooting Useful Information 20 46 Using the LI 6400 20 ...
Страница 587: ...Diagnostics and Utilities Sys Utility Programs Using the LI 6400 21 15 EBVpd t C guess EBSatVap _EBvap_kPa ...
Страница 593: ...Part VI Programming ...
Страница 594: ......
Страница 622: ...Programming with LPL Compiler Directives 22 28 Using the LI 6400 22 ...
Страница 846: ...Index I 16 Using the LI 6400 ...