Precision temperature-controlled water bath

Abstract

The water bath described was designed primarily to furnish an improved environment for microwave microcalorimeters, but would also be useful for thermometer calibration, standard cells (suitably insulated), and other physical and chemical measurement systems. The bath and its associated temperature controller operate at any temperature between 18 and 28°C which is not more than 6°C below the ambient temperature. The bath provides a temperature stability of ±25 μ°C over a 24 h period when measured with a 100-sec time constant. The short-term stability measured with a 0.7 sec time constant is between ±70 and ±7 μ°C, depending on the location within the bath and the magnitude of the energy exchange between the heating and cooling mechanisms. The bath temperature change caused by an ambient temperature change of 2°C is less than 5 μ°C. © 1968 The American Institute of Physics.