Time evaluation for the steady state condition of the weight before the measurements

Abstract

The temperature difference between the weight and its surrounding is an important parameter in the evaluation of the waiting time required by the weights to reach a steady state condition before starting a measurement, because the thermal gradients cause the thermal convection effect on the mass during the weighing process. In this study, investigation of both theoretical and experimental applications were carried out to evaluate the steady state condition of the weight before the calibration. Two kinds of unsteady state heat conduction equation were introduced, theoretical calculation results were compared to experimental results, and comparisons were very satisfactory for a 20 g weight. Then theoretical calculations were extended for different initial temperatures and for different weights. It was realized that the steady state condition of the waiting time was less dependent on initial temperature, but greatly dependent on the sizes of the weights.