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Description: | Hunterian Museum G.1986.101 (typed on spirit gummed label removed). MILLIAMPERES K FOR RADIO FREQ ONLY ADMIRALTY PATTER 7560 E.T.E.I. LTD MODEL 505 Serial No. 320755 THERMOCOUPLE 1940 GRADE 2 RES+.4 ohm J.(Makers trade plate with operating details on the face of the instrument). DES after ARSONVAL,Jacques-Arsene,d'. 1882 Paris, France. DES after SCHWEIGGER,Johann,Salomo,Christoph. 1820 Halle, Germany. DES after OERSTED,Hans,Christian. 1819 Copenhagen. Denmark. DES after THOMSON,William,Lord,1st Baron Kelvin of Largs. circa 1867 This is a radio frequency milliampere meter that has a J type thermocouple with the junction welded as published by V. M. Hickson in the Journal of Scientific Instruments, volume 17, pages 182-186, 1940. The junction acts as a resistance to a radio signal and in effect heats itself in effect becoming a prometer with a milliameter output scale. The current produced in the thermocouple junction, whch is proportional to the temperature, is then read by a moving coil galvanometer on a scale of 0-500 millamperes. Since the instrument is temperature sensitive it can be zeroed by turning the screw on the face of the instrument which alters the tension of the small spring that is situated in front of the dial. | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
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