HFP01 - snímač teplotního toku

HFP01 is a sensor for measuring the heat flow in the soil or the heat flow passing through building structures. The body of the sensor is made of a mixture of ceramic and plastic and has very little intrinsic thermal resistance.

When measuring the heat flux of a given object, the HFP01 sensor can already be built into this object or it can also be attached to the object externally.

Principle of operation

The sensor sensor converts thermal energy into electrical energy using a series of thermocouples that measure the differential temperatures of the ceramic-plastic body surfaces. The output signal of the HFP01 is a small DC voltage proportional to the heat flux and the sensor does not need any external power supply for its operation. The polarity of the output voltage determines the direction of the heat flow.

The HFP01 sensor can be connected directly to the MINILOG or via the amplifier to the M4016 station. Of course, a millivoltmeter with a corresponding voltage range can also be used to measure the output signal and thus also the heat flow.

When calculating the heat flux, the sensor voltage must be divided by its sensitivity. This is given by the sensor constant and each sensor has it listed in the accompanying documentation. The typical value of this constant is 50 uV/W/m2. The calculation is automatically provided in the MINILOG and in the M4016 unit after setting the multiplicative coefficient A1 in the respective measuring channel.


HFP01 can be used to measure the thermal resistance of building structures and thermal conductivity according to ISO 9869, ASTM C1046 and ASTM 1155. The calibration complies with the standards (National Physical Laboratory, GB) for thermal conductivity and resistance according to ISO 8302 and ASTM C177.

The measuring point should be equipped with at least two sensors that ensure a spatial averaging of the heat flow. To reduce the number of output signals, these sensors can be connected in series with one output voltage.

When measuring the heat flux in the soil and when high measurement accuracy is required, it is more appropriate to use the HFP01SC model (self-calibrated with a built-in heating plate). However, the price of this sensor is more than double compared to the HFP01 sensor.

Basic technical parameters


50 µV/W/m2

Temperature range-30 °C to +70 °C
Sensor temperature resistance< 6,25 10-3 K.m2 /W
Measuring range+2000 to -2000 W.m-2
Typical measurement accuracy (within 12 hours)+5 to -15% in normal soil, +5 to -5% in walls
Dimensionsdiameter 80mm
thickness 5mm
Standard cable length5 metrů
Price list