User manual

Hukseflux Thermal Sensors
HFP01SC Manual v0811 page 17/33
1.5 Additional quality assurance
If possible, additional measures for quality assurance of the
measurement can be programmed.
It is suggested to generate an error message if E
sen2
is larger
than the factory delivered E
sen
by more than 5%, and smaller by
more than 20%.
A possible error source is that there has been too much
fluctuation between of the heat flux in the soil during the
calibration process. As a limit we suggest to allow the
measurements at t = 0 and t = 180 to differ no more than 10 %
of the signal amplitude during calibration V
amp
of formula 2.
Summarising: possible quality checks:
1: E
sen2
< 0.8 E
sen
2: E
sen2
> 1.05 E
sen
3: V
sen
(0) - V
sen
(360) < 0.1 V
amp