The 'Microtimer'

Abstract

AN electronic timing device called the 'Micro-timer' has been produced by R. K. Dundas, Ltd., The Airport, Portsmouth. This measures the time interval between the making, or alternatively, the breaking, of two electrical contacts, or between any other combination of contacts. In addition it may be operated, without contacts, by a suitable valve amplifier in conjunction with, for example, a photo-electric cell. The time indication is given by the position of a pointer moving over the dial of a meter, and the standard instrument has ranges covering 10 to 1,000 milliseconds for full-scale deflexion. It operates entirely from the standard A.C. mains, although a battery model is available. Tests show that the instrument has negligible zero drift, is simple to calibrate and use and is of rugged construction. After taking a measurement, the deflexion of themeter is maintained for several minutes without appreciable drift; throwing a switch brings the meter back to zero for the next measurement. The accuracy claimed is within ± 2 per cent of the full scale deflexion on any range, even allowing for violent changes in mains voltage or changes of the valves.