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).
Enquiries be made for an electrical instrument to measure condenser capacities.
| Identifier | ExFiles\Box 165\3\ img003 | |
| Date | 14th June 1919 | |
| To O.O. from EFC. X.975 ~6033 EFC2/A14.6.19. X 2434 X 1782 X.975. - RE ELECTRICAL INSTRUMENT FOR THE MEASUREMENT OF CONDENSER CAPACITIES. X. 2512 Will you kindly send out enquiries to various electrical instrument makers for an alternating current instrument reading up to 50 milliamperes. It should be stated that we require this for the direct comparison of condenser capacities, for which purpose we place the instrument in series with the condenser to be tested across 200 volts A.C. at 40 periods per second, and measure the capacity current taken by the condenser. If these particulars are given, the makers should understand what it is we require. It might be stated also that it would be decidedly convenient if a non-inductive resistance were supplied with this instrument to enable us to take readings of alternating voltages, reading up to 250 volts. We do not know if there will be an instrument on the market answering to these requirements, but we would certainly like enquiries to be made. EFC. (upside down text at bottom) H.R. 235A (500) (T) (S.D. 40B. 25-4-17) Bm. 2/156/13. | ||