Campbell Scientific 253-L and 257-L (Watermark 200) Soil Matric Potential Sensors - Manual (Page 31)

253-L and 257-L Soil Matric Potential Sensors
;{CR10X}
01: 30.0000 Execution
Interval (seconds)
;Turn on AM16/32
1: Do (P86)
1: 41
Set Port 1 High
;Loop to measure five 107 probes and five 253's
2: Beginning of Loop (P87)
1: 0
Delay
2: 5 Loop Count
;Advance to next multiplexer channel
3: Do (P86)
1: 72 Pulse Port 2
;10 msec delay to allow switch to settle
4: Excitation with Delay (P22)
1: 1 Ex Channel
2: 0 Delay W/Ex (0.01 sec units)
3: 1 Delay After Ex (0.01 sec units)
4: 0 mV Excitation
;Measure soil temperature
5: Temp (107) (P11)
1: 1 Reps
2: 1 SE Channel
3: 1 Excite all reps w/E1, 60Hz, 10ms delay
4: 1 -- Loc [ T107_C_1 ]
5: 1.0 Multiplier
6: 0.0 Offset
;Measure 253 sensor
6: AC Half Bridge (P5)
1: 1 Reps
2: 14 250 mV Fast Range
3: 2 SE Channel
4: 2 Excite all reps w/Exchan 2
5: 250 mV Excitation
6: 11 -- Loc [ kOhms_1 ]
7: 1 Multiplier
8: 0 Offset
;Convert Half Bridge reading to resistance (k-Ohm)
7: BR Transform Rf[X/(1-X)] (P59)
1: 1 Reps
2: 11 -- Loc [ kOhms_1 ]
3: 1 Multiplier (Rf)
;Apply nonlinear equation from 5.3.2
8: Z=X*Y (P36)
1: 1 -- X Loc [ T107_C_1 ]
2: 1 -- Y Loc [ T107_C_1 ]
3: 6 -- Z Loc [ WP_kPa_1 ]
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