Abstract
The basic examination has been made for the development of a calorimeter detecting a nano-watt output voltage and an efficiency of a newly constructed calorimeter has been tested.
The representative improvements of the calorimeter are as follows; (1) improvement of the thermomodule for the exclusion of temperature noise incident to atmospheric pressure change, (2) improvement of a circuit regulating the sensibility of the thermomodule for the reduction of the base-line drift, (3) temperature stabilization of a water bath immersing the calorimeter, and (4) elimination for the electrostatic and electromagnetic coupling noise. The precision of the calorimeter was less than 0.02μV 4K-124h-1 (0.18μW) for the base line drift in a long time and 0.016μV (0.144μW) for the noise-level of the base line.
The linear relation of the thermal detection to the step-wise supply of the electric energy by about 1μW has been found in the devised calorimeter. As an efficiency test of the calorimeter, calorimetric measurement of a Zn/O2 coin-type cell at low generating power has been carried out, resulting in good effect.
