TESTBOY TB 60 Bedienungsanleitung Seite 21

Measuring technique 3: at the ignition distributor / ignition coil
High-voltage cable between distributor and ignition coil. Move the recording head - as shown - to a point near the high-voltage cable
connecting the distributor to the ignition coil or to where all high-voltage cables of the cylinders are found together.
Multi-cylinder petrol engines without distributor. Move the detecting head near to a point where the high-voltage wire of each cylin-
der is bundled. No measurement is possible if not all the high-voltage wires are bundled. This is because of the differences in how
far apart the recording head is from each high-voltage wire.
Specifications
Engine types: Petrol engines
2 stroke (1 – 4 cylinders)
4 stroke (1, 2, 3, 4, 5, 6, 8, 12 cylinders)
Detection technique: detecting ignition spark noise
Item to be detected: high-voltage cable or ignition cable
Calculation of the engine speed
The engine speed can be calculated on the basis of the measured frequency. The calculation formula is as follows:
n = 60 x f x 1 / PR
"n" stands for the engine speed
"f" stands for the frequency of the high-voltage ignition pulse.
"PR" stands for the ratio coefficients between "f" and "n".
The PR value can be ascertained on the basis of the following engine table:
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Operating
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Testboy TB 60