A.C. voltmeter, 0-125
Date: circa 1925
Inventory Number: 1997-1-1049
Classification: Voltmeter
Subject:
Maker: Weston Electrical Instrument Corporation (founded 1888)
Cultural Region:
Place of Origin:
Dimensions:
15.8 × 14.9 × 9.2 cm (6 1/4 × 5 7/8 × 3 5/8 in.)
Description:
A black bakelite box with an arc-shaped window in front that shows a scale inside. The scale is nonlinear with the distances between units increasing as the voltage increases, and has a range of 0 to 120 (volts). Below the scale is a reflecting band. The pointer consists of two metal wires holding a thin needle that hovers over the scale.
The box has two electrical connectors on its left side which have bakelite caps.
The box has many round holes on its top side and a leather strap going over its top side attached to screws on its top left and top right corners.
The box has two electrical connectors on its left side which have bakelite caps.
The box has many round holes on its top side and a leather strap going over its top side attached to screws on its top left and top right corners.
Signedon oval plaque: WESTON / MODEL 433 No. 413 / WESTON ELECTRICAL INSTRUMENT CO., / NEWARK, N.J., U.S.A.
Inscribedaround screw in middle of oval plaque: ADJUST FOR ZERO
below scale: VOLTS / A.C. / RES.FOR 125V [illegible follows]
below scale: VOLTS / A.C. / RES.FOR 125V [illegible follows]
FunctionThis is an alternating current voltmeter, most likely of a moving iron type in which the magnetic field produced by a coil makes a piece or iron rotate, which has the needle attached.