Campbell Scientific CMP6-L, CMP11-L, and CMP21-L Pyranometers - Manual (Page 22)

CMP6-L, CMP11-L, and CMP21-L Pyranometers
TABLE 7-4. CMP21 Single-Ended Connections to Campbell Scientific Dataloggers
Wire Color
Wire Label/
Description CR9000(X),
CR5000, CR3000,
CR1000, CR800
CR510, CR500,
CR10(X)
21X, CR7, CR23X
White Pyranometer Sig Single-ended analog Single-ended analog Single-ended analog
Blue Pyranometer Ref AG
Yellow Thermistor Volt Excite VX or EX E EX
Black Thermistor Sig Single-ended analog Single-ended analog Single-ended analog
Brown Thermistor Ref AG
Clear Shield G
7.3 Programming
This section is for users who write their own datalogger
programs. You do not need to read this section if using our Short
Cut Program Generator, or connecting the pyranometer to a
prewired enclosure or CWS900 Wireless Sensor Interface. Our
prewired enclosures include a datalogger program. Refer to the
Wireless Sensor Manual for programming information if using a
CMP6 or CMP11 with a CWS900. NOTE
7.3.1 Solar Radiation Measurements
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
7-5. Programming examples are given for both average and daily total solar
radiation.
The pyranometers output a low level voltage ranging from 0 to a maximum of
up to 20 mV, in natural light, depending on the calibration factor and radiation
level.
This voltage output is measured using either a differential voltage instruction
(VoltDiff() in CRBasic or Instruction 2 (P2) in Edlog) or a single-ended
voltage instruction (VoltSE() in CRBasic or Instruction 1 (P1) in Edlog).
Nearby AC power lines, electric pumps, or motors can be a
source of electrical noise. If the sensor or datalogger is
located in an electrically noisy environment, the
measurement should be made with the 60 or 50 Hz
rejection integration option as shown in the example
programs. CAUTION
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