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 comparative testing and subsequent standardisation of Ferranti ammeters.
| Identifier | ExFiles\Box 168\5\ img188 | |
| Date | 1st July 1930 | |
| To R.{Sir Henry Royce} from F.C. c. c. C.E. c. c. D.{John DeLooze - Company Secretary} c. c. Hor. LPC2/ADA.7.30. X.3498. FERRANTI AMMETERS. Some time since writing our PC1/AD27.11.29 it was considered that in view of the high commercial, financial and technical standing of Messrs. Ferranti Ltd. we should obtain from that firm a half dozen ammeters of grouped instrument board type made up in our standard finish, these to be tested in parallel with the Park Royal instruments referred to in the above mentioned report. This course has been pursued and the Ferranti instruments have turned out to be equally satisfactory technically as those of Park Royal manufacture. sticking. There have been slight troubles in each case but these have been shown to be altogether due to the instruments being of the open type, which sticking troubles are readily caused by the entrance of particles of foreign matter (particularly ferrous particles) when scrupulous care to avoid such entrance was not taken. Although the half dozen Ferranti instruments have not done an equivalent total mileage with those of the Park Royal, nevertheless the total mileage has been sufficient, and the results sufficiently satisfactory to warrant standardisation, and as a result a standardisation | ||