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).
Acceptable performance variation of A.T. speedometers with temperature changes.
| Identifier | ExFiles\Box 50\4\ Scan175 | |
| Date | 14th March 1928 | |
| BY. {R.W. Bailey - Chief Engineer} c. EFC. {E. Fowler Clarke - Electrical Engineer} c. CWB. c. ROY. {Mr H. Royce - Buyer} V6305 EP {G. Eric Platford - Chief Quality Engineer} 13/H14.3.28. re. A.T. SPEEDOMETERS. With reference to EFC {E. Fowler Clarke - Electrical Engineer} 3/T5.3.28 and EEC1/T7.3.28. for the instrument to read 5.1% low when the temperature is increased from 17.8 to 30.3°C is rather excessive, and we consider steps should be taken for this to be taken up with the makers, as we understand that they have been guaranteed within 4%. I also suggest that if 4% is to be condoned we should specify a correct reading at at least 30°C, as it is considered that the temperature on the instrument board may at times reach this temperature. We are attempting to make tests to confirm this on complete finished cars in London, but I suggest this test should be made on Experimental cars. In any case we consider it is advisable to be on the safe side so that under no consideration should the instrument read less than the actual car performance. I should like to receive a specification from the makers as to what they consider the minimum variation of temperature should be, and at what temperature the instruments are considered correct, which we suggest, as above, should be 30°C, so that in case of complaint of unsatisfactory reading of instruments on test, the instruments can be returned to the makers for attention. EP. {G. Eric Platford - Chief Quality Engineer} | ||