HFP01 SENSOR SPECIFICATIONS
E
sen
(nominal)
50 µV/W. m
-2
(exact value on calibration certificate)
cal = 0, Tcal =20°C
Sensor thermal
conductivity
0.8 W/mK
Sensor thermal
resistance R
th
< 6.25x10
-3
Km
2
/W
Response time
(nominal)
± 3 min (equals average soil)
Range
+2000 to -2000 W.m
-2
Non stability
< 1% change per year (normal meteorological / building
physics use)
Required readout
1 differential voltage channel or possibly (less ideal)
1 single ended voltage channel. When using more than
one sensor and lacking input channels, consider putting
several sensors in series, and work with the average
sensitivity.
Expected voltage
output
Meteorology: -10 to +20mV Building physics: -10 to 75mV
(exposed to solar radiation)
Power required
Zero (passive sensor)
Resistance
2 Ohm (nominal) plus cable resistance
Required
Φ = V
sen
/ E
sen
Sensor dimensions
80mm diameter, 5mm thickness
Cable length,
5 meters, 5mm
Weight including 5m
cable, transport dim.
0.2 kg
transport dimensions 32x23x3 cm
CALIBRATION
Initial Calibration
Accuracy
±3%
Calibration
traceability
The "guarded hot plate" of National Physical Laboratory
(NPL) of the UK. Applicable standards are ISO 8302 and
ASTM C177.
Recalibration interval Dependent on application, if possible every 2 years, see
Appendix 11.3
OPTIONS
Extended cable
Additional cable length x metres; AC100 amplifier; LI 18
hand held readout; extended temperature range
Enabling better research outcomes in soil, plant & environmental monitoring.
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