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 Exide Hydrometer Type S1, comparing its features to the standard model.
| Identifier | ExFiles\Box 44\5\ Scan079 | |
| Date | 14th May 1925 | |
| EFC. JB.103. X.3741. RE EXIDE HYDROMETER TYPE S1. This type of hydrometer appears to be quite good as compared with the standard type. Firstly, having a straight barrel it is much easier to clean and it eliminates the flow in the tube due to the drawing down which is so often eminent in the standard type. Secondly, it does not require so much acid to be drawn from the cell to obtain a reading. The float is quite free when floating in the acid and does not show any tendency to stick, it also reads about .005 low but this is not sufficient error to be concerned about. The complete hydrometer is smaller and much neater than the standard. One point which could be improved, is to provide some means of making the rubber bulb more secure when fitted on to the barrel as this seems to be rather on the loose side and is likely to come off when in use. Mainly this hydrometer seems to be quite suitable for supplying to production chassis. EFC/GJ. | ||