Images(2)

reflecting galvanometer

Datecirca 1950

Inventory Number1997-1-0382

ClassificationReflecting Galvanometer

Subject

Maker Rubicon Company fl. 1930s - 1960s

User Department of Chemistry, Harvard University founded 1791

Cultural Region

Place of Origin

Place of Use

Dimensions15.7 × 19 × 25.2 cm (6 3/16 × 7 1/2 × 9 15/16 in.)

Material

DescriptionGalvanometer housed in a rectangular wooden cabinet with rectangular window showing frosted glass scale marked every millimeter and labeled every centimeter on the top and bottom. The top row is labeled from 5-0-5 cm and the bottom row is labeled from 0-10 cm. Horizontally mounted mounted black oblong bakelite panel with two celluloid terminals on right side of cabinet and brass fine zero adjustment knob near front of righthand side. Brass coarse zero adjuster slide scale mounted on top of cabinet. The left side of the cabinet has a 2-pronged plug for an optical source (missing).

Signedon metal plaque mounted on front of cabinet: RUBICON COMPANY/ ELECTRICAL INSTRUMENT MAKERS / PHILADELPHIA MADE IN U.S.A.

Inscribedon metal plaque mounted on front of cabinet: COARSE ZERO ADJUSTING LEVER ON TOP OF CASE / FINE ZERO ADJUSTING KNOB ON RIGHT SIDE on metal plaque mounted above two-prong plug: 6 VOLTS on top of cabinet written on masking tape: CHEM 60

FunctionA self-contained galvanometer with a movable coil wrapped around the frame of the galvanometer. The coil is suspended between the poles of a magnet, and when a current is applied, the coil twists in response to the interaction of the current through the coil and the magnetic field generated by the magnet. This galvanometer was used in conjunction with a 6-volt optical source to make voltage measurements. The light beam reflects from the mirror on the galvanometer movement and this deflection can then be read from the scale on the exterior of the wooden cabinet.

ProvenanceFrom the Department of Chemistry, Harvard University, 12/1980.