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).
Electrical characteristics for a Weston R.P.M. Indicator, Instrument Model 267.
| Identifier | ExFiles\Box 33\4\ Scan226 | |
| Date | 5th April 1926 | |
| X.178 2 5.4.26. X.1782 -WESTON R.P.M. INDICATOR. INSTRUMENT MODEL 267. No.37043. Millivolts for full scale deflection 506 Milliamperes for full scale deflection 14.3 Hence resistance of instrument = 35.4 ohms. _________ EFC. | ||