Campbell Scientific 253-L and 257-L (Watermark 200) Soil Matric Potential Sensors - Manual (Page 28)

253-L and 257-L Soil Matric Potential Sensors
;Apply Temperature correction and sensor
;Calibration to kOhm measurements.
;Temperature correct kOhms
8: Z=X/Y (P38)
1: 2
X Loc [ kOhms ]
2: 4 Y Loc [ CorFactr ]
3: 3 Z Loc [ WP_kPa ]
;Apply calibration slope and offset
9: Z=X*F (P37)
1: 3
X Loc [ WP_kPa ]
2: 7.407 F
3: 3 Z Loc [ WP_kPa ]
10: Z=X+F (P34)
1: 3
X Loc [ WP_kPa ]
2: -3.704 F
3: 3
Z Loc [ WP_kPa ]
;Send measurements to final storage hourly
11: If time is (P92)
1: 0
Minutes (Seconds --) into a
2: 60 Interval (same units as above)
3: 10 Set Output Flag High (Flag 0)
12: Set Active Storage Area (P80)
1: 1
Final Storage Area 1
2: 60 Array ID
13: Real Time (P77)
1: 1220
Year,Day,Hour/Minute (midnight = 2400)
14: Average (P71)
1: 1
Reps
2: 1 Loc [ Tsoil_C ]
15: Sample (P70)
1: 1
Reps
2: 3 Loc [ WP_kPa ]
7.3.2 253 Program Examples
7.3.2.1 Program Example #3 — Five 107 Temperature Probes and Five 253’s on AM16/32
and CR1000
The following example demonstrates the programming used to measure five
107 temperature probes and five 253 sensors on an AM16/32 multiplexer
(4x16 mode) with the CR1000 datalogger. In this example, a 107 temperature
probe is buried at the same depth as a corresponding 253 sensor. The linear
equation is used and the non-linear equation is included in the program notes.
To use the non-linear equation, remove the linear equation from the program
and uncomment the non-linear equation. Voltage range codes for other
CRBasic dataloggers are shown in TABLE 7-1. Sensor wiring is shown in
TABLE 7-7.
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