Measurement of Detonation: A Description of the R.A.E.‐Mulliard Detonation Unit and Meter

METHODS in general use for assessing detonation in the cylinders of internal combustion engines depend upon training the ear of the engine operator. For single‐cylinder aero‐engine test units it is possible to detect detonation by listening to the various noises produced by the engine. The constant association of the noises produced by detonation and the effects of detonation on the engine parts enables the operator to correlate these two factors. After a training on a particular engine it is possible for him to estimate the destructive quality of different degrees of detonation by listening to the engine noises resulting from detonation. It is, however, very difficult to assess the degree of detonation by such methods, which depend on aural estimation alone.