Campbell Scientific HMP155A Temperature and Relative Humidity Probe - Manual (Page 34)

Appendix B. Example Programs
B.3.2 Edlog Vapor Pressure and Saturation Vapor Pressure
Program
Below is an example CR10X program. Information about using it with other
Edlog dataloggers are provided in the program’s comments.
;Turn the HMP155A on.
;
01: Do (P86)
1: 41
Set Port 1 High ;Jumper wire from SW12V control to C1
;Green wire (C1) if using SW12V device
;For CR23X or CR5000 use 49 for SW12V internal
;control port
;Pause 5 seconds before making measurements so the
;probe can stabilize on true readings.
;
02: Excitation with Delay (P22)
1: 1
Ex Channel
2: 0 Delay W/Ex (units = 0.01 sec)
3: 500 Delay After Ex (units = 0.01 sec)
4: 0 mV Excitation
;Measure the HMP155A temperature.
;
03: Volt (SE) (P1)
1: 1
Reps
2: 5 2500 mV Slow Range ;CR510, CR500 (2500mv); CR23X (1000 mV);
21X, CR7 (5000 mV)
3: 3 SE Channel ;Yellow wire (SE 3), white or purple wire (AG)
4: 1 Loc [ T_C ]
5: .14 Mult
6: -80 Offset
;Measure the HMP155A relative humidity.
;
04: Volt (SE) (P1)
1: 1
Reps
2: 5 2500 mV Slow Range ;CR510, CR500 (2500mv); CR23X (1000 mV);
21X, CR7 (5000 mV)
3: 4 SE Channel ;Blue wire (SE 4), white or purple wire (AG)
4: 2 Loc [ RH_frac ]
5: .001 Mult
6: 0 Offset
;Turn the HMP155A off.
;
05: Do (P86)
1: 51
Set Port 1 Low ;Jumper wire from SW12V control to C1
;Green wire (C1) if using SW12V device
;For CR23X or CR5000 use 59 for SW12V internal
;control port
;Compute the saturation vapor pressure.
;The temperature must be in degrees Celsius.
;
06: Saturation Vapor Pressure (P56)
1: 1
Temperature Loc [ T_C ]
2: 3 Loc [ e_sat ]
B-6