HFP01SC self-calibrating heat flux sensor™ is a heat flux sensor for use in the soil. It offers the best available accuracy and quality assurance of the measurement. The on-line self-test verifies the stable performance and good thermal contact of sensors that are buried and cannot be visually inspected and taken to the laboratory for recalibration. The self-test also includes self-calibration which compensates for measurement errors caused by the thermal conductivity of the surrounding soil (which varies with soil moisture content), for sensor non-stability and for temperature dependence.
HFP01SC measures soil heat flux in W/m². It is used when the highest level of quality assurance and a high measurement accuracy are required. In essence, HFP01SC is a combination of a heat flux sensor and a film heater. The heat flux sensor output is a voltage signal that is proportional heat flux through the sensor. At a regular interval the film heater is activated to perform a self-test. The self-test results in a verification of sensor contact to the soil and in a new sensitivity that is valid for the circumstances at that moment. The latter is called self-calibration. Implicitly also cable connection, data acquisition and data processing are tested. The result is a much improved accuracy & quality assurance of the measurement relative to measurements with conventional sensors such as model HFP01.
|Measurement Range:||-2000 to +2000 W/m²|
|Sensitivity (nominal):||60 x10⁻⁶ V/(W/m)²|
|On-line functionality testing:||self-test including self-calibration|
|Sensing area:||8 x10⁻⁴ m²|
|Sensor thermal resistance:||81 x10⁻⁴ K/(W/m²)|
|Rated operating temperature range:||-30 to +70°C|
|IP protection class:||IP67|
|Film heater resistance:||100 Ω ±10%|
|Film heater rated power supply:||9 to 15 VDC|
|Interval between self-tests:||6 hr|
|Heating interval duration:||180 s|
|Power consumption daily average:||0.02 W|
|Standard cable length:||2 x 5 m|
|Options:||longer cable length (10, 15, 20, 30, 40 m)|