Campbell Scientific 110PV Surface Temperature Probe - Manual (Page 22)

110PV Surface Temperature Probe
Example Program for CR10X
;{CR10X}
;This program measures a single 110PV-L probe utilizing the
;P5 instruction once a second and stores the average
;temperature in degrees C every ten minutes.
*Table 1 Program
01: 1
Execution Interval (seconds)
;Measure 110PV-L Probe
1: AC Half Bridge (P5)
1: 1
Reps
2: 25 2500 mV 60 Hz Rejection Range
3: 1 SE Channel
4: 1 Excite all reps w/Exchan 1
5: 2500 mV Excitation
6: 1 Loc [ V_Vx ]
7: 1.0 Multiplier
8: 0.0 Offset
;Convert ratio-metric output to resistance (next three instructions)
2: Z=1/X (P42)
1: 1
X Loc [ V_Vx ]
2: 2 Z Loc [ Vx_V ]
3: Z=X+F (P34)
1: 2
X Loc [ Vx_V ]
2: -1.0 F
3: 3 Z Loc [ Vx_V1 ]
4: Z=X*F (P37)
1: 3
X Loc [ Vx_V1 ]
2: 4990 F
3: 4 Z Loc [ Rx ]
;Correct for cable resistance (see 110PV-L cable label for resistance value F in Ohms)
5: Z=X+F (P34)
1: 4
X Loc [ Rx ]
2: 0.0 F
3: 5 Z Loc [ Rtherm ]
;Convert resistance to Temperature
6: Steinhart-Hart Equation (P200)
1: 1
Reps
2: 5 Source Loc (R)(Ohms) [ Rtherm ]
3: 6 Destination Loc (Deg C) [ Temp_C ]
4: 1.12924 A
5: -3
x 10^n
6: 2.34108 B
7: -4
x 10^n
8: 8.77547 C
9: -8
x 10^n
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