Humboldt State University ® Department of Chemistry
Robert A. Paselk Scientific Instrument Museum
Enclosed Lamp & Scale Galvanometer
Leeds & Northrup Co.
Philadelphia
Humboldt State College; 1960
Usage: The reflecting galvanometer is a sensitive instrument for measuring current. It consists of a magnet coil with an attached mirror suspended between the poles of a magnet by a thin gold ribbon above and a coiled gold wire below. When an electric current is introduced into the magnet coil it induces a magnetic field, causing the coil to rotate in proportion to the current. The mirror allows the user to see very small deflections, and thus to measure very small currents, by observing a distant reflected scale. In this instrument an illuminated image of a line is projected through a small telescope onto the mirror, which reflects it onto the built-in scale on the ground glass window on the front of the case.
The instrument on display in the case is from the physics department and is in new, unused condition. An identical instrument, seen in the web photo, was used in the physical chemistry lab. It was used by students in the physical/analytical chemistry laboratory at HSU for sensitive measurements in conjunction with the L&N K-3 Potentiometer as seen in the photograph from a 1963 HSC recruitment brochure.
Description: The smooth grey painted metal case has gently rounded corners. It is 6 1/4" wide x 13 5/8" deep x 9 1/4" high. The instrument on display in the case is in unused, new condition, the web instrument is in excellent condition, noting the labels sruck on it to aid studnet use.
Research: This instrument is illustrated and described on p740 of the Cenco 1960 Catalog (J-300).
