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Sensitivity analysis for guarded-hot-plate apparatus: A methodology based on orthogonal experiment designs



Robert R. Zarr, James J. Filliben


Results and analyses of a sensitivity study of six control factors on the response of the National Institute of Standards and Technology 500 mm guarded-hot-plate apparatus are presented. The effects of four factors held constant as well as three uncontrolled environmental factors were also examined. Sixty-six thermal conductivity measurements were conducted at a mean temperature of 310 K for a pair of fibrous-glass specimens (120 kg∙m-3) having nominal dimensions 500 mm in diameter and 26 mm in thickness. The apparatus response was studied using an orthogonal fractional factorial design, a one-factor-at-a-time design, and a full factorial design for a subset of factors from the fractionated design. The results indicate that the most important factor affecting the thermal conductivity measurement was the temperature difference across the air space separating the central meter plate and the surrounding guard plate, described here as the gap temperature offset (ΔTg). The study also revealed an interaction between the gap temperature offset and the temperature difference across the specimen (ΔTavg). An empirical model for the results of the sensitivity study is presented. Results of the gap temperature offset (ΔTg) are similar to published results from another guarded-hot-plate apparatus.
Journal of ASTM International


experimental design, fractional factorial, full factorial, guarded hot plate, high density molded fibrous glass board, orthogonal, ruggedness, sensitivity, thermal conductivity, thermal insulation


Zarr, R. and Filliben, J. (2014), Sensitivity analysis for guarded-hot-plate apparatus: A methodology based on orthogonal experiment designs, Journal of ASTM International (Accessed April 16, 2024)
Created September 9, 2014, Updated February 19, 2017