gaussmeter or magnetometer

Date1960s

Inventory Number2012-1-0035

ClassificationMagnetometer

Subject

Maker Rawson Electrical Instrument Company 1918 - 1968

Cultural Region

Place of Origin

Place of Use

Dimensions14.6 × 30.5 × 20.2 cm (5 3/4 × 12 × 7 15/16 in.)

Material

Accessoriesthe probe 2012-1-0036 plugs to this instrument

DescriptionRectangular walnut case with rounded leather handle and hinged lid.

Inside is the instrument, with a bakelite casing. Fan-shaped window in center of face, with the Rawson standard pointer (with a double, o-shaped section over the mirror) with a reflective band under the scale.

Double scale, from 0-12 and 0-40 kilogauss.

Over the scale there are two discoidal dials with settings 0-30 and 0-9. Also a counter labelled "0-999 GAUSSES". A bakelite button with a silver ring labelled "CAL.ADJ" and "LOCK"(with an arrow). A nine-prong plug to which the probe (2012-1-0036) attaches.

Under the scale are two electrical connectors labelled "EXT.GALV", a circular knob with settings 0.4-40, and the raised disk-shaped section with the "ZERO" and "CLAMP" dials.

Signedprinted on face of meter: KILOGAUSSES / RAWSON ELECTRICAL INSTRUMENT CO. / CAMRBIDGE, MASS. / (left column) TYPE 501 INDICATOR / NO. 16921 / CAL. AT 25C / (right column) USE ONLY WITH PROBE #16920 / TYPE 820

Inscribedon raised disk below meter: UNCLAMP BEFORE USING service tag: DATE Jan. '85 / Name University of Nottingham / Material _____ / #16921 / (left column) Repair / Quote / (illegible) / (center column) Type 820 / Case # ____ / Cover # _____ / Cords ____ / (right column) K / P / Foreign

Curatorial RemarksThe probe was made at a later date, when the company had changed name to Rawson-Lush. It is not certain whether they were used together but it is likely as they were both used in Nottingham.

FunctionGaussmeters are used to measure the strength of manetic field.

According to the Rawson Instruments Bulletin 820 Gaussmeters, "A motor-driven rotating coil is the sensing element. When placed in a magnetic field, the coil acts as a simple AC generator and the voltage output is a true measure of the field. (...)". They advertise in this bulletin an improved output indication system with a "better than 1/10 of 1% accuracy".

ProvenanceGift of the Lush family, December 2012.

Historical AttributesAccording to the service tag, it appears to have been used (or owned by) the University of Nottingham, in the 1980s. (See inscriptions).