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).
Page describing the function of a recording stylus and diagram roll for a measuring instrument.
| Identifier | ExFiles\Box 113\2\ scan0164 | |
| Date | 11th November 1930 guessed | |
| -3- These functions are repeated second by second, which prevents the pointer from falling back, and sets it every second to the corresponding value. The value indicated by the pointer thus always corresponds to the average speed of the preceding second. Fig. 1 is a graph of the function of the measuring movement and of the movements of the pointer and recorder stylus which it releases. It will be seen that the maintained position is only applied in one direction, and that downwards (towards zero) while a positive speed variation is already set on train before the end of the second measurement. The Recording Stylus A sapphire which requires no attention as practically no wearing takes place, is connected by gearing with the pointer spindle, and this gives the same indications as the pointer. The Diagram Roll This is a translucent blue tinted paper, the diagrams are traced in white, and are indelible. The forward feed of the chart is proportional to the speed of rotation, i.e. to the distance traversed or to the revolutions per minute and is from 1 to 2 m/m per metre or 0.5 to 1 m/m per revolution. The feed roller punctures the forward feed of the chart on the zero line and on that of maximum speed at the rate of 1 puncture every 3 m/m, which allows the distance traversed to be very easily determined. To facilitate reading, a double puncture is shown every 60 m/m, say every 60 or 30 metres run, or 60 or 30 revolutions effected. We recommend that the forward movement should only be determined by counting the dots, as the length measured may vary slightly by reason of the possible expansion or contraction of the diagram. To facilitate reading, the diagram charts, 65 m/m wide, are ruled to the recording height of 60 m/m.{Mr Moon / Mr Moore} | ||