Galvanometer

Physics

Accession Number: 2020.ph.855

Description:

A small metal instrument, painted grey-brown. The instrument has three adjustable feet at the corners of its triangular base. On the front vertical surface of the instrument is a round window through which a small mirror is visible through a hole in other instrument parts. Just below this window is small knurled knob. Directly below the knob is a rectangular metal label that is attached to the instrument with four screws, one at each corner.

On the top of the instrument there is brown knurled knob. Appearing on this in white enameled lettering is the word ZERO and a double headed arrow indicating either direction for turning the knob.

On the lower front surface of the instrument, sitting on a small plate of bakelite affixed the front base of the instrument, are two electrical terminals with plastic screw tops. Underneath the base of the instrument, insulated wires run from these terminals through a small hole in the base, and into the interior, of the instrument.

Alternative Name: Type 4500A galvanometer.

Primary Materials:

Metal: Iron Alloy, Metal: Other, Bakelite

Markings:

The metal label at the front of the instrument includes the following information: “GALVANOMETER
TYPE 4500A
NO. 1792
H. TINSLEY & CO. LTD.
ST. JEROME, P.Q.

The following is scratched into the bakelite surface between the electrical connections at the front of the instrument: “2190 B”

Dimensions (cm): Height = 15.5, Length = 10, Width = 10.

Function:

A galvanometer is an instrument for detecting and measuring electrical current.

In this instrument, current is measured by the deflection of a point of light reflected off a small mirror whose movement is dictated by electromagnetic effects.

Condition:

Very good: The surface of the instrument is quite dirty, with old adhesive adhering to the front and back of the instrument.

The top knob of the instrument appears to have white deposit on it.

Manufacturer: H. Tinsley & Co. Ltd. St Jerome, Quebec

Date of Manufacture: c. Early to Mid 20th Century

Provenance:

This artifact was among a small collection of galvanometers and other early electrical instruments gathered from storage at the Department of Physics in January of 2019.