From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The condition and electrical calibration of an Elliott Milliammeter No. 4808.
| Identifier | ExFiles\Box 168\5\ img031 | |
| Date | 22th September 1925 | |
| Y4622 EFC4/T22.9.25. ELLIOTT MILLIAMMETER No. 4808. This instrument appears to be in quite good order mechanically. It is nicely dead-beat and works without any sticking. Electrically, the nominal range, without any external shunt, is .150 ampere (150 milliamperes, not 1500.) The electrical calibration of this instrument is thus :- Scale proportionality fair only. Subtract 2.5% from readings above 125 divisions. Subtract 3% from readings from 50 to 125 divisions and subtract 4% below 50 divisions. The approximate resistance of the instrument between the terminals is .755 w at atmospheric temperature. Millivolts for full scale deflection 110. EFC. | ||