Vintage GM Laboratories Inc Sargent Potentiometer Galvanometer 11"

Description

Vintage Sargent Potentiometer / Galvanometer. Manufactured by E.H. Sargent & Co, Chicago - Catalog S-30260 - Serial 3366006 - Made in USA. Galvanometer - Made in Chicago, USA - G-M Laboratories Inc - Catalog No 570-103. Metal case with Bakelite knobs.

"A potentiometer is an instrument for measuring voltage or 'potential difference' by comparison of an unknown voltage with a known reference voltage. If a sensitive indicating instrument is used, very little current is drawn from the source of the unknown voltage. Since the reference voltage can be produced from an accurately calibrated voltage divider, a potentiometer can provide high precision in measurement. The method was described by Johann Christian Poggendorff around 1841 and became a standard laboratory measuring technique. In this arrangement, a fraction of a known voltage from a resistive slide wire is compared with an unknown voltage by means of a galvanometer. The sliding contact or wiper of the potentiometer is adjusted and the galvanometer briefly connected between the sliding contact and the unknown voltage. The deflection of the galvanometer is observed and the sliding tap adjusted until the galvanometer no longer deflects from zero. At that point the galvanometer draws no current from the unknown source, and the magnitude of voltage can be calculated from the position of the sliding contact." (Source: Wikipedia)

Condition

Good Overall - Gentle wear

Dimensions

11" x 8" x 6" (Width x Depth x Height)