Heater Lead Error in Calorimetry

Abstract

A summary of previous work is followed by an examination of the effects of radiation from heater leads. Solutions of the exact differential equation for particular experimental configurations have been obtained by a numerical method. For certain simple situations the solutions can be checked against partial or complete analytical solutions of the equation. It is shown that even for low temperature calorimeters a large part of the electrical energy dissipated in heater leads may be radiated unless the lead resistance is kept very low. If a significant part of the total energy supplied to the calorimeter is radiated, systematic errors may arise because, for a given calorimeter heating rate, the heater lead radiation loss will differ in the ``full'' and ``empty calorimeter'' experiments.