reflecting galvanometer
Date: circa 1900
Inventory Number: DW0314
Classification: Reflecting Galvanometer
Subject:
Maker: Robert W. Paul Instrument Company (1891 - 1919)
User: David P. Wheatland (1898 - 1993)
Cultural Region:
Place of Origin:
City of Use:
Dimensions:
24.5 × 16 × 17.5 cm (9 5/8 × 6 5/16 × 6 7/8 in.)
Description:
Galvanometer with tiny moving magnet suspended between two fixed coils enclosed in bakelite cylindrical case with short brass suspension tube above and mirror in circular viewing window below. Case is mounted on bakelite post with one brass binding post. Brass tripod base with three leveling screws.
Signedengraved on both sides of case: R.W. PAUL / HATTON GARDENS / LONDON
FunctionReflecting galvanometers are used to measure very small electrical currents and voltage differences. Instead of having a scale with a pointer, in these galvanometers a small mirror turns in the presence of electrical currents. The change of angle can be detected by shining a light at the mirror and observing the reflection on a large scale that is placed in front of the device.
ProvenanceSelected by David P. Wheatland, 13 May 1961 from E. Pontet, London.