Campbell Scientific HMP155A Temperature and Relative Humidity Probe - Manual (Page 29)

Appendix B. Example Programs
B.1 Single-Ended Voltage Measurement Examples
These examples use the single-ended voltage instruction to measure the sensor
and use the datalogger’s SW12V terminal to power the sensor only when it is
being measured. TABLE B-1 shows the wiring used for these examples.
TABLE B-1. Wiring for Single-ended
Measurement Examples
Color Description CR1000 CR10(X)
Yellow Temperature SE 2 (1L) SE 3 (2H)
Blue Relative Humidity SE 1 (1H) SE 4 (2L)
White Signal Reference AG
Jumper from
SW12V Control
C1
Red Power SW12V SW12 V
Black Power Ground AG
Clear Shield G
B.1.1 CRBasic Single-Ended Measurement Program
Below is an example CR1000 program. Other CRBasic dataloggers are
programmed similarly.
'CR1000 program to measure HMP155A with single-ended measurements
Public AirTC
Public RH
DataTable(Temp_RH,True,-1)
DataInterval(0,60,Min,0)
Average(1,AirTC,IEEE4,0)
Sample(1,RH,IEEE4)
EndTable
BeginProg
Scan(5,Sec,1,0)
'HMP155A Temperature & Relative Humidity Sensor measurements AirTC and RH:
PortSet (9,1)
Delay(0,2,Sec)
VoltSE(AirTC,1,mV2500,2,0,0,_60Hz,.14,-80)
VoltSE(RH,1,mV2500,1,0,0,_60Hz,0.1,0)
PortSet (9,0)
If RH>100 And RH<108 Then RH=100
CallTable(Temp_RH)
NextScan
EndProg
B-1