Wheatstone Bridge

Portable Wheatstone Bridge

This high quality instrument has a nice solid wooden case and robust controls and was manufactured by the Croydon Precision Instrument company, known as Cropico, in the 1950’s.
The PW1 is a manually balanced Wheatstone bridge with a usable range from 10 milliohms to 11 megohms. Four decades of switched resistances provide four-digit resolution (from 1 milliohm on the 10 ohm range to 1kohm on the 10 megohm range. Separate multiply by and divide by switches, each spanning four decades from 10 to 10,000 act to modify the scaling of the switched resistances.
There is no internal power supply: a battery of at least 2V would have been connected to the Battery terminals.