Campbell Scientific HFP01 Soil Heat Flux Plate - Manual (Page 7)

Model HFP01 Soil Heat Flux Plate
1. Introduction
The HFP01 outputs a voltage signal that is proportional to the heat flux of the
surrounding medium (usually soil). It is typically used for energy-balance or
Bowen-ratio flux systems. At least two sensors are required for each site to
provide spatial averaging. Sites with heterogeneous media may require
additional sensors.
Before installing the HFP01, please study
• Section 2, Cautionary Statements
• Section 3, Initial Inspection
The installation procedure is provided in Section 6.
2. Cautionary Statements
• Care should be taken when opening the shipping package to not damage
or cut the cable jacket. If damage to the cable is suspected, consult with a
Campbell Scientific applications engineer.
• Although the HFP01 is rugged, it should be handled as a precision
scientific instrument.
3. Initial Inspection
• Upon receipt of the HFP01, inspect the packaging and contents for
damage. File damage claims with the shipping company.
• The model number and cable length are printed on a label at the
connection end of the cable. Check this information against the shipping
documents to ensure the correct product and cable length are received.
• The HFP01 is shipped with a calibration sheet and an instruction manual
or a ResourceDVD.
4. Overview
The HFP01 Soil Heat Flux Plate uses a thermopile to measure temperature
gradients across its plate. Operating in a completely passive way, it generates
a small output voltage that is proportional to this differential temperature.
Assuming that the heat flux is steady, that the thermal conductivity of the body
is constant, and that the sensor has negligible influence on the thermal flow
pattern, the signal of the HFP01 is directly proportional to the local heat flux.
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