Resistance Meter

 

 

 This meter was designed for general purpose resistance measurements, probably around the period 1900 to 1910, possibly a little earlier? The instrument was made by White E.I.Co.Ltd. and has the number 7961B on the scale. I don't know of this company. Can anyone shed light on who they were and when the meter was made?

The scale is calibrated from infinity on the left to zero ohms at the right and with its 135 degrees of pointer deflection from end to end, the reading accuracy is very good. Calibration is marked from 0 to 500 with useful and wide-spaced centre scale markings.

A switch selects "Low Range" with separate terminals provided for High and Medium resistance. Although the scale is OK for the Low Range one has to multiply these reading by 200 and 2000 for medium and high resistance readings. This would have been quite a simple matter for an Edwardian electrical engineer, but with todays fallen "three Rs" standards, I suspect not too easy for a modern electrician.

Under the ebonite cover there's a space for what may have been a 4.5-volt bell battery.

return to entrance