Automatic Intercomparison of Standard Cells

A system is described whereby precise intercomparisons of standard cells are accomplished under full computer control. The results obtained indicate accuracies (one standard deviation) of ±10 nV from which the individual values of the standard cells in a maintaining group of ten cells are estimated to be accurate to ±20 nV. The major source of indeterminacy continues to be the variation of standard cell EMF due to temperature, mechanical vibration, etc.