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 required instruments for production testing of ignition coils and correcting previous instructions.
| Identifier | ExFiles\Box 165\3\ img012 | |
| Date | 22th January 1920 | |
| To By.{R.W. Bailey - Chief Engineer} from Ck.{Mr Clark} c. Hy{Tom Haldenby - Plant Engineer} c. Mr. Brock. X.975. 86033 CK{Mr Clark}2/T22.1.20. X.1627 - INSTRUMENTS FOR PRODUCTION TESTING X.975. Test No.2 in our recommended instructions for production testing of ignition coils involves the use of a Weston A.C. milli-ammeter similar to the one which is already in use for the production testing of condensers. Unless some satisfactory arrangement can be arrived at by which the same instrument can be used for the two purposes (this would be rather difficult at present as the two sections of testing are done at different places) it will be necessary to obtain a further milli-ammeter of this type. A shunt for reading the voltage of the mains, though perhaps desirable, we do not consider really necessary, as unless the supply voltage is so low as to make the difference appreciated on a lamp, the actual variations are not of sufficient consequence to enter into the matter. On the said par.No.2 of instructions, we have just noticed an error - the words "fall below" should be replaced by the words "not exceed". Would you kindly see that this is altered on your copies. In our original recommendations for instruments, we stated that a third combined volt-ammeter would probably be necessary. The Production Dept. have not so far received a third instrument of this type, contaiging | ||