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).
Testing and standardisation of Exide hydrometers for production use.
| Identifier | ExFiles\Box 44\5\ Scan102 | |
| Date | 8th March 1928 | |
| X3741 To EY/Mtn. from EFC. c. Despatch Stores. EFC10/T8.3.28. The 25 Exide hydrometers recently sent to us for test have been tested and found reasonably correct. One of these has been selected as reading particularly correct, as a standard of reference for testing further hydrometers on production. Hydrometers should be tested at each end of the scale for correctness with acid of densities 1120 and 1300. We suggest that every so often, say once every two months, this semi-standard hydrometer which we have suitably marked be returned to us for checking. In the way suggested it will then not be necessary to send us hydrometers for production testing as has been done so far, i.e. if you can conveniently arrange for such testing to be done elsewhere. The semi-standard instrument is sent to B by Mtn. and the remaining 24 are herewith returned to the Stores. EFC. | ||