Measurement of the Nonlinearity of Heat-Flux Sensors Employing a \(\hbox {CO}_2\) laser

  • E. W. M. van der Ham
  • C. M. Beer
  • M. J. Ballico
Part of the following topical collections:
  1. TEMPMEKO 2016: Selected Papers of the 12th International Symposium on Temperature, Humidity, Moisture and Thermal Measurements in Industry and Science


Heat-flux sensors are widely used in industry to test building products and designs for resistance to bushfire, to test the flammability of textiles and in numerous applications such as concentrated solar collectors. In Australia, such detectors are currently calibrated by the National Measurement Institute Australia (NMIA) at low flux levels of 20 W \(\cdot \) m\(^{-2}\). Estimates of the uncertainty arising from nonlinearity at industrial levels (e.g. 50 kW \(\cdot \) m\(^{-2}\) for bushfire testing) rely on literature information. NMIA has developed a facility to characterize the linearity response of these heat-flux sensors up to 110 kW \(\cdot \) m\(^{-2}\) using a low-power \(\hbox {CO}_2\) laser and a chopped quartz tungsten–halogen lamp. The facility was validated by comparison with the conventional flux-addition method, and used to characterize several Schmidt–Boelter-type sensors. A significant nonlinear response was found, ranging from (\(3.2 \pm 0.9\))% at 40 kW \(\cdot \) m\(^{-2}\) to more than 8 % at 100 kW \(\cdot \) m\(^{-2}\). Additional measurements confirm that this is not attributable to convection effects, but due to the temperature dependence of the sensor’s responsivity.


Fire testing Heat-flux sensor calibration Nonlinearity Schmidt–Boelter gauges 



The authors would like to thank intern Tessa de Groot from the Hague University—Delft, the Netherlands, for her contribution in collecting data and implementing improvements to the measurement set-up.


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2017

Authors and Affiliations

  • E. W. M. van der Ham
    • 1
  • C. M. Beer
    • 1
  • M. J. Ballico
    • 1
  1. 1.National Measurement InstituteLindfieldAustralia

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