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).
Inquiry regarding the minimum distance between instruments to prevent magnetic interference, specifically the speedometer, ammeter, and petrol gauge.
| Identifier | ExFiles\Box 165\4\ img230 | |
| Date | 29th December 1933 | |
| URGENT WST 81807 Hs{Lord Ernest Hives - Chair}/Wst. BY/RD2/W.29.12.33. Proximity of Speedometer to other instruments. Will you please let us know the minimum distance that must be allowed between the magnetic type speedometer and ammeter or petrol gauge, to ensure that the latter will be free from any magnetic interference. On the Bentley we assume that the revolution counter will also affect these two small instruments if placed too close. Will you also please confirm that the new lightened type instruments now on test have similar interference characteristics as the larger ones now used on Production. 6 1/2" between centres. WST. BY/RD. | ||