The effective temperature at which fingertips sense thermal effusivity and the bias of measurements at room temperature

Abstract

Thermoreceptors in the fingertips sense the temperature drop upon contact with an object and in that way its thermal effusivity.But, at which effective object temperature? That is the question that this article answers by perturbation analysis for slightly temperature dependent thermal properties.How much deviate thermal effusivity measurements at room temperature from fingertip measurements at said effective object temperature? This question is also answered by perturbation analysis.The bias may be up to 7% using nearly isothermal measurement methods and up to around 19% using fingertip-mimicking measurement methods for airy materials like wool.Rewriting the temperature model reveals a felt delay and its dependency on the thermal contact resistance between fingertip and object.