Heat flux sensors

# An overview of heat flux sensors

This short article will provide to the reader an overview of heat flux sensors from the definition, working principle and applications.

## Heat flux sensors are a Seebeck sensors

• Heat Flux Sensors are based on the Seebeck effect.
• When heat passes through the sensor, the sensor generates a voltage signal. This voltage signal is proportional to the heat passing through the sensor such as: HF ∝ V where HF = Heat Flux, in W/m² and, V = Voltage, in V.

## Examples of heat flux sensors

• gSKIN® XM 26 9C : Size of 4.4mm x 4.4mm & it resolves 0.41 W/m2 – 7.9 µW – 140 µK. More information here.
• gSKIN® XP 26 9C : Size of 10mm x 10m and it resolves 0.09 W/m2 – 9 µW – 30 µK. More information here.
• gSKIN® XI 26 9C : Size of 18mm x 18m and it resolves 0.03 W/m2 – 9 µW – 10 µK. More information here.

## How do they work?

The gSKIN® Heat Flux Sensor is a highly sensitive Seebeck Sensor.

The sensitivity of a Seebeck Sensor depends on the thermocouple material quality used in the sensor and the number of thermocouples used.

A thermocouple consists of two separate thermopiles (n-type and p-type). These thermopiles are highly integrated in the sensor substrate, which leads to high sensitivity sensor modules.

## How to use them?

All Heat Flux Sensors generate a voltage signal which is proportional to the heat that passes through the sensor element such as HF = V / S where HF = Heat Flux, in W/m2 V = Voltage, in µV and S = Sensor sensitivity, in µV/(W/m2).

In most applications, this voltage signal is in the µV range. The voltage signal is converted into the heat flux value by dividing it by the sensor sensitivity.

As the voltage signal is in the µV range, it is crucial to have a voltage logging unit with high voltage resolution. For R&D applications, we recommend one of the following datalogging solutions:

• gSKIN DLOG dataloggers
• Pico Technology High-Resolution Data Acquisition
• Keithly Volt Meters

If gSKIN® components are to be integrated, it is recommended to design specific read-out electronics.

## Recommanded readings to go further

• Discover all the Use Cases related to our technology, here.
• Explore our product line, here.
• Discover all the peer-reviewed publications using our technology, here.