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).
Test results for a Lucas rheostat with a Clayton S.2.C.A. heater, showing resistance, RPM, temperature, and noise levels.
| Identifier | ExFiles\Box 137\2\ scan0145 | |
| Date | 3rd September 1938 | |
| Rm{William Robotham - Chief Engineer}/Std.4/MH.{M. Huckerby}3.9.38. TESTS ON LUCAS RHEOSTAT WITH CLAYTON S.2.C.A. HEATER. Resistance of rheostat at selected position. | R.P.M. | Temp. of Rheostat. | Comments on Heater Noise. 0 | 2640 | 23°C Ambient temp. | Noisy. 2.12 | 2310 | 50°C | Fairly quiet 2.55 | 2010 | 60°C | Quiet 5.74 | 1600 | 87°C | Inaudible. Above tests made after heater had been running for about ½ hr. Motor speeds rise with temperature of motor and hence time of running - if heater is run long enough to attain steady temp. (several hours) max. speed of motor is 2800 r.p.m. above speeds would then rise approx. in proportion. | ||