You can know counts of the engine detonation combustion by using this unit and the PI sensor.
The PI sensor tighten torque is 2.5Kgf.m(25N.M).
How to clear counts is pushing the switch on the unit. The unit is counted one time when the kill switch turns on and off.
This is reference counts is as follows at HRC test with unleaded fuel.
Safe setting condition: 1~5 times per kilometer
Engine damage level: more than 10 times per kilometer