Campbell SR11, Инструкция по эксплуатации

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SR11 Pyranometer
7
Connections to Campbell Scientific dataloggers are given in TABLE 6-1 . The
pyranometer can be measured using either differential or single-ended
analog
ue
channels. A differential voltage measurement is recommended
because it has better noise rejection than a single-ended measurement. If a
differential channel is not available, a single-ended measurement can be used.
TABLE 6-1. Wire Colo u r, Function, and Datalogger Connection
Wire
Colo u r
Wire
Function
Differential Connection
Terminal
Single-Ended
Connection Terminal
White
Signal
High
U configured for
differential input 1 , DIFF
H (differential high,
analog ue -voltage input)
U configured for single-
ended analog
ue
input 1 ,
SE (single-ended,
analog ue -voltage input)
Green
Signal
Reference
U configured for
differential input 1, 2 ,
DIFF L (differential
low, analog
ue
-
voltage input)
2
AG or ⏚ (analog
ue
ground)
Clear Shield
AG or ⏚ (analog ue
ground)
AG or ⏚ (analog ue
ground)
1
U channels are automatically configured by the measurement instruction.
2 Jumper to AG or ⏚ with a user-supplied wire.
6.4 Programming
Programming basics are provided in the following section. A complete
program example can be found in Appendix A ,
Example Program
(p. A-1)
.
Solar radiation can be reported as an average flux density (W m –2 ) or daily total
flux density (MJ m –2 ). The appropriate multipliers are listed in TABLE 6-2 .
Programming examples are given for both average and daily total solar
radiation.
The SR11 outputs a low-level voltage ranging from 0 to a maximum of up to
35 mV, in natural light, depending on the calibration factor and radiation level.
The SR11 is measured using either the differential voltage instruction
( VoltDiff ) or a single-ended voltage instruction ( VoltSE ). A differential
voltage measurement is recommended because it has better noise rejection than
a single-ended measurement. If a differential channel is not available, a single-
ended measurement can be used. The acceptability of a single-ended
measurement can be determined by simply comparing the results of single-
ended and differential measurements made under the same conditions.
6.4.1 Input Range
The output voltage of the SR11 is usually –0.1 to 50 mV per 1000 W m
–2
.
When estimating the maximum likely value of sensor output, a maximum value
of solar radiation of 1100 W m –2 can be used for field measurements on a
horizontal surface.