A Computer Controlled Automatic System for Measuring the Conductivity and Hall Effect in Semiconducting Samples

A unique computer controlled automatic system for measuring the conductivity and Hall effect in semiconducting samples is described. The system features a small process control computer which runs a temperature programmable liquid helium Dewar, a magnet, and a data acquisition system. Fifty temperature points can be preprogrammed in any desired distribution over the range 4.2–400 K. The control computer ensures that the system is virtually foolproof in terms of operator blunder and system malfunction. Data acquisition is on punched paper tape with hard copy output. Data, converted from paper tape to cards, are analyzed by a high speed computer. Turnaround times (from sample loading to full analysis of data) of as low as 6 h have been achieved.