FHF06 heat flux sensor

Heat flux measurement in high temperature environments

FHF06 is a high temperature foil heat flux sensor that can be used for temperatures up to 250 °C. This is made possible by its all-polyimide design, not using any glues. Other members of the FHF family, the FHF05 series range, can be used up to 120 °C maximum, which makes the FHF06 unique. The sensor is thin, flexible and versatile. FHF06 measures heat flux through the object in which it is incorporated or on which it is mounted, in W/m².

The sensor in FHF06 is a thermopile. This thermopile measures the temperature difference across FHF06’s flexible body. A type T thermocouple is integrated as well, to provide a measurement of temperature. The thermopile and thermocouple are passive sensors; they do not require power.

Multiple small thermal spreaders, which form a conductive layer covering the sensor, help reduce the thermal conductivity dependence of the measurement. With these incorporated spreaders, the sensitivity of FHF06 is independent of its environment.

Unique features and benefits

• high temperature resistance up to 250 °C continuous use
• flexible (bending radius ≥ 7.5 x 10-³ m)
• low thermal resistance
• fast response time
• integrated type T thermocouple
• robustness, including connection block for strain relief
• IP protection class: IP67 (essential for outdoor application)
• integrated thermal spreaders for low thermal conductivity dependence
• sensor foil only: may be used in vacuum

Easy to use

Using FHF06 is easy. It can be connected directly to commonly used data logging systems. The heat flux in W/m² is calculated by dividing the FHF06 output, a small voltage, by the sensitivity. The sensitivity is provided with FHF06 on its certificate and at the end of FHF06’s cable.

Robust and stable

Equipped with a connection block, which may serve as strain relief, and with potted protective covers on both sides so that moisture does not penetrate, FHF06 has proven to be very robust and stable.

FHF06 calibration is traceable to international standards. The factory calibration method follows the recommended practice of ASTM C1130 - 21.

Working with heat flux sensors

When used under high temperature conditions, the FHF06 sensitivity to heat flux may be different than stated on its certificate. See the user manual for correcting this temperature dependence. For mounting, see our application note how to install a heat flux sensor.

Suitable electronics

The combined measurement of heat flux and temperature offers you a full picture of the thermal behaviour of a system. Heat flux sensor output is a small millivolt signal. Heat flux sensors are often combined with thermocouples. We have several preferred solutions for amplification, data logging and data visualisation. See our application notes on sensor amplification or FHF sensors with Hioki dataloggers.