Vintage Sensitive Research Instrument Corp Thermocouple AC Voltmeter Model A

Description

Vintage 1950s Sensitive Research thermocouple voltmeter. Sensitive Research Instrument Corporation, New Rochelle, New York - Thermocouple Alternating Current Voltmeter - Model A - No. 303436 (device) - Serial No. 501238 (case) - D'Arsonval Thermo-Couple Type - Ranges 2-1000 Volts. Wood case, Bakelite top, glass front.

"Jacques-Arsène d'Arsonval (8 June 1851 – 31 December 1940) was a French physician, physicist and inventor of the moving-coil d'Arsonval galvanometer and the thermocouple ammeter. D'Arsonval was an important contributor to the emerging field of electrophysiology, the study of the effects of electricity on biological organisms, in the nineteenth century. The first moving-pointer current-detecting device was the galvanometer in 1820. These were used to measure resistance and voltage by using a Wheatstone bridge, and comparing the unknown quantity to a reference voltage or resistance. While useful in the lab, the devices were very slow and impractical in the field. These galvanometers were bulky and delicate. The D'Arsonval–Weston meter movement uses a moving coil which carries a pointer and rotates on pivots or a taut band ligament. The coil rotates in a permanent magnetic field and is restrained by fine spiral springs which also serve to carry current into the moving coil. It gives proportional measurement rather than just detection, and deflection is independent of the orientation of the meter. Instead of balancing a bridge, values could be directly read off the instrument's scale, which made measurement quick and easy." (Source: Wikipedia)

"The Sensitive Research Instrument Corporation was founded in 1927. The company went through some changes after its merger with Singer about 50 years ago, but was eventually bought back by its employees and exists today as part of Electrical Instrument Service (EIS) of Mount Vernon, NY. They still repair and recalibrate those meters, and build new ones on order. " (Source: Progress is Fine Blog)

Condition

Good Overall - Gentle wear

Dimensions

8" x 7.75" x 4" (Width x Depth x Height)