A computer controlled DC measuring system for use in low temperature calorimetry

Abstract

An automatic control and recording system for use in low temperature calorimetry is described, in which all measurements are taken with a precision digital voltmeter. In addition to a general description of the control system and the computer program, some details are included of the design of programmable power supplies and a novel low level scanning switch. The system uses an 8k byte minicomputer which also handles the data analysis, but fully automatic operation could be realized with a much smaller minicomputer or microprocessor. Although the main purpose of the development was to automate a tedious experimental technique, small but significant improvements have resulted in the measurements from what has turned out to be a reasonably versatile system.