HTX datasheet(13/36 Pages) RMT

13 / 36 page

OPERATING MANUAL. HTX SERIES

Page 13 of 36

FUNCTIONALITY TEST

All the HTX thermoelectric Heat Flux Sensors adhere to high manufacturing

standards. Before shipping, the performance of each Heat Flux Sensor is

individually checked and calibrated. All the data are advised in

Specifications of the Sensor.

However, external factors (e.g. transportation, prior use), may affect the

functionality of the Sensor module. Before the permanent installation, the

Sensor functionality must be tested.

5.1 Checking of AC Resistance

The electrical resistance testing is done using a standard multimeter via a

four-wire probe measurement. The resistance measurement must be done

without any applied temperature gradient (e.g. with the Sensor hanging in

air holding it at the cables).

The resistance must be in the range specified in the Sensor’s respective

datasheet. This value does not include the resistance of the cables.

Resistance below 0.1 ohm indicates a short circuit, while resistance higher

than the value stated in the datasheet indicates physical wearout of the

Sensor and/or its cables. In both cases, the Sensor is not functional and

must be replaced.

5.2 Checking of Figure-of-Merit.

The Sensor is a thermoelectric module device. Performance and

functionality of the Sensor can be examined by two parameters: the AC

Resistance (see above) and Figure-of-Merit. In some cases functionality

checking only by AC resistance measurements is not enough. Particularly in

the case of probable failure, and necessity to investigate reasons of this.

Checking of Z together with ACR gives much more information about

functionality of the thermoelectric Sensor.

HTX Folha de dados(PDF) 13 Page - RMT Ltd.