![background image](http://html1.mh-extra.com/html/campbell/kh20/kh20_user-manual_3876052016.webp)
KH20 Krypton Hygrometer
8
Public rho_w
Alias kh(1) = kh_mV
Alias kh (2) = ln_kh
Units panel_temp = deg_C
Units batt_volt = volts
Units kh_mV = mV
Units ln_kh = ln_mV
Units rho_w = g/m^3
'*** Data Output Tables ***
'Processed data
DataTable (stats,True,-1)
DataInterval
(0,OUTPUT_INTERVAL,Min,10)
Minimum
(1,batt_volt,FP2,False,False)
Average
(1,panel_temp,FP2,False)
Average
(2,kh(1),IEEE4,False)
EndTable
'Raw time-series data.
DataTable (ts_data,True,-1)
DataInterval
(0,SCAN_INTERVAL,mSec,100)
Sample
(1,kh_mV,IEEE4)
EndTable
'*** Program ***
BeginProg
Scan
(SCAN_INTERVAL,mSec,3,0)
'datalogger
panel
temperature.
PanelTemp
(panel_temp,250)
'Measure
battery
voltage.
Battery
(batt_volt)
'Measure
KH20.
VoltDiff
(kh_mV,1,mV5000,1,TRUE,200,250,1,0)
ln_kh = LOG(kh_mV)
rho_w = ln_kh/xkw
CallTable
stats
CallTable
ts_data
NextScan
EndProg
6. Maintenance and Calibration
The KH20 sensor is designed for continuous field application and requires little
maintenance. The tube ends for the KH20 have been sealed with silicone
elastomer using an injection-mould method. Therefore, the tubes are protected
from water damage, and the KH20 continues to make measurements under rainy
or wet conditions. If the water tends to pool up on the tube window and blocks
the signal, you can turn the sensor head at an angle so as to shed the water off the
tube window. The rain shield protects the electronics box and the connectors
from moisture.