Automatic Measuring System for a Control of Standard Cells

The automatic measuring system developed in the Electrotechnical Laboratory to monitor standard cells requiring a lot of measurements is described. It is composed of a scanner, an integrating-type digital voltmeter, a programmer or minicomputer, etc., and carries out the data acquisition and processing for a maximum of 200 cells. The difference in EMF of two cells is measured precisely. To reduce the effect of the induced EMF in the scanner, a delay unit is provided, and procedures minimizing errors and evaluating random errors have been adopted. In the on-line version of system, a great part of the data processing is done during the delay and integrating time of digital voltmeter. Applying this system to the measurement of standard cells, a precision of the order of 0.1 μV has been obtained.