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).
The operating temperatures of a dynamo, ignition coil, and condenser, measured using fusible metal sentinels.
| Identifier | ExFiles\Box 51\1\ Scan225 | |
| Date | 4th September 1923 | |
| X4383 To R & E. {Mr Elliott - Chief Engineer} from EFC. {E. Fowler Clarke - Electrical Engineer} c. CJ. & FN. c. EY. c. EP. {G. Eric Platford - Chief Quality Engineer} EFC {E. Fowler Clarke - Electrical Engineer} 1/T4.9.23. x4383 x2430 x4079 TEMPERATURES OF DYNAMO, IGNITION COIL AND CONDENSER FOUND BY MEANS OF TEMPERATURE INDICATING SENTINELS. We have arranged suitable temperature indicating sentinels of fusible metals in such a manner as to indicate very nearly the working temperatures of the above three units, and the indications of these sentinels to date are as follows :- DYNAMO. After melting a number of 68° and 73° sentinels on dynamos, we have found the maximum temperature to be in the neighbourhood of 82°. 82° sentinels have twice been melted on 4GII, twice on 6GII, and once on 7GII, remaining unmelted on 2GII and 3GII. 87° sentinels are now being arranged for 4GII and 6GII. IGNITION COIL. 73° sentinels have melted on 3GII, 4GII, 6GII and 7GII and have been replaced by 77° sentinels, two of which have melted, once on 7GII (bracket position), and once on 4GII (engine position). CONDENSER. Of 73° sentinels fitted to condensers on 3GII, 4GII, 6GII and 7GII, one on 4GII has become melted, but only after considerable time. Sentinels have all been replaced by 65°, which so far as we know at the moment are all unmelted, even on 4GII. EFC. {E. Fowler Clarke - Electrical Engineer} | ||