CS105/CS105MD Barometric Pressure Sensor
4. Programming
4.1 CS105MD
Programming the MetData1 station for the CS105MD is done through
Campbell Scientific’s Short Cut program. Short Cut includes code in the
.DLD file to correct for elevation.
4.2 CS105
Atmospheric pressure changes little with time. In most weather station
applications measuring pressure once an hour is adequate. In Examples 1 and
2 the datalogger turns on the CS105 one minute before the top of the hour with
a control port. As in the example, the execution interval must be one minute or
less. On the hour the datalogger measures the CS105, records the pressure,
and turns off the CS105.
In Example 3 the CS105 is measured every execution interval. The datalogger
turns the CS105 on and waits one second for the CS105 to warm up, before the
measurement is made.
The execution interval must be long enough to accommodate the one second
delay, to warm up the CS105, and all the other measurement and processing
instructions in the program.
In Example 4, the CS105 is measured every execution interval with a 21X. An
excitation channel is used to turn the CS105 on and off.
A CR10(X), CR500, and CR510 excitation channel
cannot be used to turn the CS105 on and off because
the maximum excitation voltage is 2.5 volts. The
CS105 control requires 5 VDC.
WARNING
In the example programs the pressure is reported in millibars (mb). To report
pressure in different units, multiply (Edlog Instruction 37) the measured
pressure by the appropriate conversion factor (Table 2).
TABLE 2. Conversion
Factors for Alternative
Pressure Units
To Find
Multiply by
kPa 0.1
mm of Hg
0.75006
in of Hg
0.02953
PSI 0.0145
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