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. Ltd. regarding the change in reading of eddy-current speedometers with temperature and time.
| Identifier | ExFiles\Box 50\4\ Scan134 | |
| Date | 15th August 1927 | |
| X4308 EPC5/T. 15th August, 1927. Messrs. The A.T. Speedometer Co. Ltd., 20, Avonmore Road, West Kensington, W.14. Dear Sirs, With further reference to the A.T. eddy-current type speedometer concerning which we have already had with you an amount of correspondence regarding the change of reading with temperature, and as a result of which you have supplied us with instruments with a smaller temperature coefficient in the reading. We are now anxious for information from you concerning the possibility of change in reading of these instruments with time (observation taken at the same temperature as originally) due to possible loss of magnetism of the permanent magnets. Thanking you in anticipation for your views or impressions in this matter. Yours faithfully, A.M.I.E.E, FOR ROLLS-ROYCE LIMITED. | ||