Campbell Scientific HFP01 HFP01 Soil Heat Flux Plate - Page 8

Model HFP01 Soil Heat Flux Plate NOTE The HFP01's output is in millivolts. To convert this measured voltage to heat flux, it must be divided by the plate's calibration constant. A unique calibration constant is supplied with each sensor. To get the soil heat flux at the surface, use at least two HFP01s to measure soil heat flux at a depth of 8 cm; a TCAV Averaging Soil Thermocouple to measure the temporal change in temperature of the soil layer above the HFP01; and a CS616, CS650, or CS655 water content reflectometer to measure soil water content (see Figure 6-1). The temporal change in soil temperature and soil water content are used to compute the soil storage term. The -L extension in the model name (i.e., HFP01-L) indicates a user-specified cable length. This manual refers to the sensor as the HFP01. The sensor's cable can terminate in: • Pigtails that connect directly to a Campbell Scientific datalogger (option -PT). • Connector that attaches to a prewired enclosure (option -PW). Refer to www.campbellsci.com/prewired-enclosures for more information. • Connector that attaches to a CWS900 Wireless Sensor Interface (option -CWS). The CWS900 allows the probe to be used in a wireless sensor network. Refer to www.campbellsci.com/cws900 for more information. A general discussion about the characteristics and principles of operation of heat flux sensors is shown in Appendix A. 5. Specifications Features: • Compatible with most of our contemporary and retired dataloggers • Compatible with the CWS900-series interfaces, allowing it to be used in a wireless sensor network Compatibility Dataloggers: CR800 series CR1000 CR3000 CR5000 CR9000(X) CR7X CR510 CR10(X) CR23X 21X Operating Temperature: -30° to +70°C Plate Thickness: 5.0 mm (0.20 in) Plate Diameter: 80.0 mm (3.15 in) 2