This is a black instrument which stands on three adjustable screw legs with plastic feet. The instrument is cylindrical, with an broader round base. On the underside of the circular base there is a oval plastic attachment with labels “SENS.0001(“mu symbol”)A/mm”, “C.D.R.X. 19000(Ohm Symbol)”, “PERIOD 14 sec”, “RESIST 511(Ohm Symbol)”, “Cat. No. 2500 F”. This can be rotated to view the label, or tucked away out of sight. On the metal base there is an etching “102811”.
The cylinder of the instrument emerges from the centre of the base. On one side, it has a rectangular opening which is covered in glass held on with a metal surround screwed to the cylinder. Visible behind this is the galvanometer mechanism and a small circular mirror attached to a fine a vertical wire. In front of this window, affixed to the base, there are two electrical terminals topped with plastic screw caps. On top of the cylinder there is a brass knob with the following labels “Made in U.S.A”, “Zero Adjuster”, “Coil Clamp”.
Accession Number: 2009.ph.176
Alternative Name: Type R Galvanometer
Primary Materials: Metal: Iron Alloy, Plastic, Glass
On the metal base there is an etching “102811”. On top of the cylinder there is a brass knob with the following labels “Made in U.S.A”, “Zero Adjuster”, “Coil Clamp”.
Dimensions (cm): Height = 22cm, Diameter = 13cm
Galvanometers are used to measure small changes in electrical current.
Very Good or Excellent: The case of the instrument is in very good condition with very few marks or scratches. The interior mechanism also appears in good condition. The small mirror an attached wire is resting in a lax position, but this may be because it has been adjusted for storage.
2009.ph.10; 2009.ph.177; 2009.ph.178; 2009.ph.21; 2015.ph.638; 2015.ph.664; 2015.ph.665
Leeds & Northrup Co. Philadelphia, Pennsylvania, USA.
Date of Manufacture: Mid 20th Cent. (c. 1930-1970)
Provenance: Collection of Dr. Martin Lee.
Additional Information and References:
Historical Notes: