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).
Technical memorandum discussing the limitations and suitability of the Wimperis accelerometer for different applications.
| Identifier | ExFiles\Box 113\2\ scan0014 | |
| Date | 11th January 1923 | |
| To hs.{Lord Ernest Hives - Chair} from Rn.{Mr Robinson} THE ACCELEROMETER. The Wimperis accelerometer appears to me to have been primariarly designed for use on a small firm, where apparatus for recording the performance of the chassis is distinctly limited, and where probably the tester has neither the time nor the capacity for calculating decelerations, tractive resistances, or accelerations, from the velocity time graph. There is no doubt that it provides a direct rough and ready method of obtaining results which can otherwise only be procured with the expenditure of a certain amount of time and trouble, but these results are affected to such an extent by rotational energy, and the large personal error in observation, as to be of but little use as permanent record. When a firm is equipped with a large variety of apparatus including dynamometers, to measure the tractive effort actually delivered to road wheels, and in addition, is able to put the car on the track and give the time necessary to make accurate observations and calculations, it seems rather absurd to attempt to get parallel results from an instrument the very nature of which is condusive to errors to the extent of 10%. It may be argued that since the Wimperis recording accelerometer is used with success on the railways, its simpler counterpart should be equally useful on automobiles, but apart from the fact that all motion in a car is very much more violent and spasmodic than that of a locomotive, the case seems to me to be analogous to that of a Barometer and a contd:- | ||