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).
Tests to show the effect of temperature on the calibration of Bentley speedometers.
Identifier | ExFiles\Box 59\2\ Scan225 | |
Date | 16th August 1933 guessed | |
BENTLEY SPEEDOMETERS. TESTS TO SHEW TEMPERATURE EFFECT ON CALIBRATION. A.T. INSTRUMENT NO. G.382. Scale Reading (M.P.H.) | R.P.M. of Drive. | Temperature. | Calibration. --- | --- | --- | --- 60 | 770 | 18°C. | 3.5% F.{Mr Friese} 60 | 774 | 25°C. | 3.0% F.{Mr Friese} 60 | 785 | 35°C. | 1.5% F.{Mr Friese} 60 | 795 | 45°C. | Correct. 60 | 810 | 55°C. | 1.5% S. 60 | 820 | 65°C. | 2.5% S. When driven at 797 R.P.M. at 60 M.P.H. as on Bentley with 10/41 axle. Smith "Nemag" instrument. Scale Reading (M.P.H.) | R.P.M. of Drive. | Temperature. | Calibration. --- | --- | --- | --- 60 | 767 | 35°C. | 4.0% F.{Mr Friese} 60 | 772 | 45°C. | 3.0% F.{Mr Friese} 60 | 780 | 55°C. | 2.0% F.{Mr Friese} 60 | 790 | 65°C. | 1.0% F.{Mr Friese} Hs{Lord Ernest Hives - Chair}/H.E.West. | ||