Calibration of Heat Stress Monitor and its Measurement Uncertainty

  • Can EkiciEmail author


Wet-bulb globe temperature (WBGT) equation is a heat stress index that gives information for the workers in the industrial areas. WBGT equation is described in ISO Standard 7243 (ISO 7243 in Hot environments—estimation of the heat stress on working man, based on the WBGT index, ISO, Geneva, 1982). WBGT is the result of the combined quantitative effects of the natural wet-bulb temperature, dry-bulb temperature, and air temperature. WBGT is a calculated parameter. WBGT uses input estimates, and heat stress monitor measures these quantities. In this study, the calibration method of a heat stress monitor is described, and the model function for measurement uncertainty is given. Sensitivity coefficients were derived according to GUM. Two-pressure humidity generators were used to generate a controlled environment. Heat stress monitor was calibrated inside of the generator. Two-pressure humidity generator, which is located in Turkish Standard Institution, was used as the reference device. This device is traceable to national standards. Two-pressure humidity generator includes reference temperature Pt-100 sensors. The reference sensor was sheltered with a wet wick for the calibration of natural wet-bulb thermometer. The reference sensor was centred into a black globe that has got 150 mm diameter for the calibration of the black globe thermometer.


Black globe temperature Calibration Dry-bulb temperature Measurement uncertainty Natural wet-bulb temperature Wet-bulb globe temperature (WBGT ) 



Wet-bulb globe temperature


Natural wet-bulb temperature, units of \({^{\circ }}\hbox {C}\)


Air temperature, units of \({^{\circ }}\hbox {C}\)


Black globe temperature, units of \({^{\circ }}\hbox {C}\)


  1. 1.
    D. Bethea, K. Parsons, The Development of a Practical Heat Stress Assessment Methodology for Use in UK Industry (Loughborough University, Norwich, 2002)Google Scholar
  2. 2.
    D. Moran, K. Pandolf, Y. Shapiro, Y. Heled, Y. Shani, W. Mathew, R. Gonzalez, J. Therm. Biol. 26, 4 (2001)Google Scholar
  3. 3.
    N.R. St-Pierre, B. Cobanov, G. Schnitkey, J. Dairy Sci. 86, E52 (2003)CrossRefGoogle Scholar
  4. 4.
    T. Kjellstrom, S. Gabrysch, B. Lemke, K. Dear, Glob. Health Action (2009). doi: 10.3402/gha.v2i0.2082
  5. 5.
    ISO EN 7730, Ergonomics of the Thermal Environment—Analytical Determination and Interpretation of Thermal Comfort Using Calculation of the PMV and PPD Indices and Local Thermal Comfort Criteria (ISO, Geneva, 2005)Google Scholar
  6. 6.
    ISO 7243, Hot Environments—Estimation of the Heat Stress on Working Man, Based on the WBGT Index (ISO, Geneva, 1982)Google Scholar
  7. 7.
    K. Parsons, Ind. Health 44, 3 (2006)CrossRefGoogle Scholar
  8. 8.
    B. Wilson, U.S. Patent No. 4,592,661 (U.S. Patent and Trademark Office, Washington, 1986)Google Scholar
  9. 9.
    IEC 60751, Industrial Platinum Resistance Thermometers and Platinum Temperature Sensors (IEC, Geneva, 2008)Google Scholar
  10. 10.
    ASTM E2593, Standard Guide for Accuracy Verification of Industrial Platinum Resistance Thermometers (ASTM, New York, 2012)Google Scholar
  11. 11.
    S. Hasegawa, J.W. Little, J. Res. NBS A 81A, 81 (1977)Google Scholar
  12. 12.
    C. Meyer, J. Hodges, P. Huang, W. Miller, D. Ripple, G. Scace, Calibration of Hygrometers with the Hybrid Humidity Generator (NIST, Bethesda, 2008)CrossRefGoogle Scholar
  13. 13.
    Series 2500 Benchtop Two-Pressure Humidity Generator Operation and Maintenance Manual (Thunder Scientific Corporation, Albuquerque, 2003)Google Scholar
  14. 14.
    E. El-Din, M. Mekawy, K. Ali, Metrol. Meas. Syst. 16, 2 (2009)Google Scholar
  15. 15.
    S. Sokhansanj, Encyclopedia of Agricultural, Food, and Biological Engineering (Taylor and Francis, New York, 2003)Google Scholar
  16. 16.
    L. Gaul, G. Underwood, J. Invest. Dermatol. 19, 1 (1952)CrossRefGoogle Scholar
  17. 17.
    American Society of Heating, Refrigerating and Air Conditioning Engineers (Ashrae Handbook Fundamentals, Atlanta, 2001)Google Scholar
  18. 18.
    BIPM, IEC, Evaluation of measurement data—guide for the expression of uncertainty in measurement (JCGM, 2008)Google Scholar
  19. 19.
    G. Buonanno, A. Frattolillo, L. Vanoli, Measurement 29, 127 (2001)CrossRefGoogle Scholar
  20. 20.
    ISO EN 7726, Ergonomics of the Thermal Environment-Instruments for Measuring Physical Quantities (ISO, Geneva, 1998)Google Scholar

Copyright information

© Springer Science+Business Media New York 2017

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringYildiz Technical UniversityIstanbulTurkey
  2. 2.Gebze Calibration DirectorateTurkish Standard InstitutionAnkaraTurkey

Personalised recommendations