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).
Specification and quotation for an oscillograph, rectifying valve, and electrostatic voltmeter.
| Identifier | ExFiles\Box 41\2\ Scan025 | |
| Date | 23th May 1923 | |
| To R.{Sir Henry Royce} from EFC. c. CJ. X3646 EFC3/T23.5.23. RE OSCILLOGRAPH, RECTIFYING VALVE AND ELECTROSTATIC VOLTMETER. X3985 X3646 X4563 OSCILLOGRAPH. After some amount of correspondence with the Cambridge & Paul Instrument Co., we have arrived between us at a specification of oscillograph equipment suitable for the purposes we have in mind, including particularly the study of vibrator regulator control for dynamos. We now send for your examination and approval copy of their final quotation. RECTIFYING VALVE. You will remember having suggested the use of a Wimshurst machine for the purpose of supplying high D.C. potentials to insulating materials for leakage tests, etc. the leakages occurring on low potentials (if any) being no indication of what will take place on high potentials. In view of the fact of our now having in our possession a H.T. transformer, we suggested that we utilise a suitable rectifying valve in conjunction with a suitable H.T. condenser, which could probably fairly easily make, as an alternative to a Wimshurst machine, and we now have a quotation from the G.E.C. Co. for one of their type U2 rectifying valves suitable for voltages up to 7000. This would be capable of supplying ample current for high tension D.C. leakage tests. The price is £11.0.0. less 20% + packing and postage - delivery from stock. ELECTROSTATIC VOLTMETER. Whichever method (Wimshurst machine or rectifying valve) were used for supplying H.T. direct current, a H.T. voltmeter would be desirable and would also be useful for H.T. A.C. potential measurements. We have accordingly obtained a quotations, and the one from Messrs. Everett, Edgcumbe & Co. Ltd., seems to be the most suitable. They offer us a double range 0 to 5000 and 0 to 10,000 volts electrostatic voltmeter at £17.12.0; or alternatively a double range 0 to 5000 and 0 to 20,000 volt instrument, at £20.0.0., subject to 2½% discount, inclusive of delivery. Contd. | ||