The COP sensor can be used as an additional pick-up probe for automotive oscilloscopes. It is used to test the efficiency of a COP ignition system and to determine whether it produces ignition sparks with the correct duration. The COP sensor transforms the induced signal into a voltage pulse (shown on the oscilloscope screen) with the ignition coil’s high-voltage chain. These values are in direct relation to the voltaic arc produced by the spark plug. Due to the variety of ignition coils with differing designs it should be noted that the COP sensor cannot determine the exact value of the voltage where the ignition spark appears. It can however be used for comparative analyses between the different cylinders in order to determine which cylinder is defective.
COP stands for Coil-On-Plug electronic ignition. There are no high-voltage cables in automotive COP ignition systems and the coil itself is located on top of the spark plug. In most cases the coils are placed on top of the cylinder head on the cylinder block. This position is beneficial because exhaust gases cannot heat up the coils there. In other words - the COP is the ignition system of the modern automobile. The lack of high-voltage cables means the reliability of the ignition systems is significantly increased and it has fewer leaks. Using a separate coil on top of each spark plug allows the interval between ignitions to be increased. This means that the residual magnetic field in the coil dissipates better; the coil operates better in higher engine revolutions.