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).
Letter from Peto & Radford regarding the use of Cadmium Electrodes for testing accumulator plates.
| Identifier | ExFiles\Box 44\5\ Scan002 | |
| Date | 28th January 1925 | |
| X.4049. Works, Dagenham Dock, Essex TELEPHONE VICTORIA 3667. 4 LINES PRIVATE BRANCH EXCHANGE. TELEGRAMS CONCENTRATION, SOWEST, LONDON. Manufacturers of P&R Accumulators. Established 1889 PETO & RADFORD Proprietors - Pritchett & Gold and E.P.S. Company Ltd. 50 GROSVENOR GARDENS LONDON, S.W.1. DIRECTORS: SIR ARCHIBALD G.{Mr Griffiths - Chief Accountant / Mr Gnapp} GOLD K.C. GRAHAM MENZIES G.R.N. MINCHIN WILLIAM PETO C.R.D. PRITCHETT T.W. PRITCHETT YOUR REF EFC.6/T. OUR REF WP/HA 281 January 28th 1925. E.Fowler Clark Esq, Messrs.Rolls-Royce Limited, Nightingale Road, DERBY. re Cadmium Electrode Dear Sir, We have used Cadmium Electrode for testing the condition of the Positive and Negative plates for many years. Cadmium is positive to both elements in the voltaic sense. At one time we used to sell a pocket voltmeter in which one wire was attached to a pencil of Cadmium enclosed in a sleeve of perforated ebonite. Cadmium should be perfectly pure but not scraped bright as a certain amount of oxidization is necessary. When a cell is discharged to 1.8 volts the positive should show 2.05 with the Cadmium, and the negative, .25. It is common practice to use this metal for deciding whether positives or negatives have not sufficient capacity to carry through the discharge on equal terms. The readings are taken when the cell is discharged at its normal rate. You may be interested to know that at one time there was a primary secondary battery on the market in which the positive element was an ordinary peroxide plate | ||