Weston Galvanometer

Collections · Physics

Accession Number: 2015.ph.651

Instrument Name: Weston Galvanometer


The object consists of a black, rectangular metal box supported on four feet. On the top of the instrument, there is a glass window display for viewing the measurement scale (range: -30 – +30). There are two small knobs on the top of the instrument, labelled “1″ and “2″, and two on one side connected by a wire. A label on the top of the instrument identifies it as produced by the Weston Electrical Instrument Corp. On the bottom, there is an instructional label detailing the use of the instrument.

Alternative Name: Galvanometer, Ammeter, Ampmeter

Primary Materials: Steel, Glass, Wire, Paper


On top label: “WESTON” “Model 440 No 17400″ “Adjust for Zero”
“Weston Electrical Instrument Corp., Newark, N.J., U.S.A.”

On small knobs on top of instrument: “1″ “2″

On scale: “Weston Galvanometer”, scale going from -30 to +30, marked in increments of ten
“Res.= 16.5 Ohms 1 Div. = 0.25 x10^-6 Amp. Approx.”
“External Res. For Critical Damping = 700 Ohms”
“Model 440 No. 17400″

On bottom label:
“Use of Protecting Resistor
This Galvanometer contains a protecting Resistor of 5000 Ohms to prevent damage to the movable element during preliminary testing.
When using the Galvanometer always press key marked “1″ first and then, if greater sensitivity is desired, press key marked “2″.
The right hand binding po[---] this Galvanometer is marked “+”. If the pointer deflects toward the “+” end of the scale, the polarity of the circuit is as indicated by the binding po[---] marking. If the pointer deflects toward the “-” end of the scale, the polarity of the circuit is opposite to that indicated by the binding post marking.”
Critical Resistance
This Galvanometer operates most satisfactorily when connected in a circuit, the resistance of which is equal to the external critical damping resistance stated on the scale card. For resistances lower than this value, the motion of the pointer will be overdamped, and for higher resistances it will be underdamped.
F 914-1M-10-46″

Dimensions (cm):

Height = 5.5 cm Width = 9.5 cm Length = 14 cm


Measures electrical power of a circuit. This instrument is portable and was meant to be calibrated by hand.


Good – some minor damage
- slight discoloration/corrosion on top label
- corrosion of screws
- wire connecting two side knobs is corroded
- label on bottom is peeling, torn, and discolored, with some words unreadable

Associated Instruments: N/A

Manufacturer: Weston


University of Toronto Physics Department

Donated to UTSIC: Yes