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).
Requesting the creation of new ignition coil temperature indicating sentinels with a higher melting point.
| Identifier | ExFiles\Box 45\4\ Scan191 | |
| Date | 21th August 1923 | |
| To H1. from EFC. EFC2/T21.8.23. X4079 RE IGNITION COIL TEMP. INDICATING SENTINELS. X.4079. A number of the 73º sentinels which you made up for our coils have melted on the coils and indicate that slightly higher temperature sentinels are required. We are therefore providing you with half a dozen wires and would like you to make up on these sentinels to melt at 77º or 78ºC. A sample 73º sentinel accompanies these, giving the correct relative position of the globule of metal. In the case of the condenser sentinels (73ºC) none of these have melted. Will you let us know the lowest temperature for which it is possible to make these sentinels ? EFC. | ||