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).
Letter to The A.T. Speedometer Co. regarding required speedometer calibration adjustments.
| Identifier | ExFiles\Box 59\2\ Scan150 | |
| Date | 27th April 1932 | |
| X6051 c. EY. c. E.{Mr Elliott - Chief Engineer} c. PN.{Mr Northey} c. CX.{Major Len W. Cox - Advertising Manager} Hs{Lord Ernest Hives - Chair}/Wst.1/AD. April 27th, 1932. The A.T. Speedometer Co. Chronos Works, North Circular Rd. London, N.W.2. Dear Sirs, Speedometer Calibration. We have noticed on several speedometers tested (80 M.P.H. dials) that from about 40 M.P.H. upwards the readings are approximately correct with a tendency in one or two instruments for the readings to be 1% low. Owing to the slight adverse effects of increase of effective tyre circumference at speed and the increase of temperature under the instrument board, we consider our instruments should read at least 3% to 5% fast above 40 M.P.H. Will you please inform us if you can do this conveniently. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||