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).
Summary of test results for Lucas Ammeters, noting issues with pointer sticking and zero error.
| Identifier | ExFiles\Box 168\5\ img345 | |
| Date | 11th December 1937 | |
| Lucas Ammeters. -3- RM{William Robotham - Chief Engineer}/RC.{R. Childs}3/JH.11.12.37. Summary. Our tests show that as regards insulation and damping of the pointer the Lucas ammeter is satisfactory. As regards reliability and accuracy while it is fairly strong mechanically it is initially inaccurate, and is in addition effected by the position in which it rests, and by a heavy over-load. We conclude however that these faults are relatively unimportant. There remain the two important points of sticking of the pointer, and zero error in respect of both which the instrument is inclined to be faulty. Those we think could be simply remedied by the makers. Therefore should the road tests give satisfactory results and this instrument go forward for standardisation, we must insist that the makers improve their methods of inspecting and assembling in order to ensure that instruments are free from these two troubles. At the same time we think that it would be better if the zero mark were made a little narrower. RM{William Robotham - Chief Engineer}/RC.{R. Childs} | ||