The use of a dial indicator gauge in the motor vehicle area depends on the additional accessories. The cylinder diameter
can be determined provided the instrument has two
inside calipers (feelers). The roundness of a cylinder, or the level running of brake- and clutch discs is also often determined with this. The play testing is also the domain of the dial gauge. If it is mounted onto the
cylinder block, and the feeler is positioned on the flywheel, one can measure, among other things, the axial play of the crankshaft. More often, in the past, the gauge was used in the setting of the delivery start in axial plunger pumps.
How it works
The distance between the individual lines on the round scale, is 0.01mm. With every full rotation the feeler is shifted 1mm further in- or outwards. This can be read off from the additional small indicator (1 segment =
1mm) display. This is, for a mechanical device, a high measuring accuracy. Inside the instrument, the movement of the feeler is transfered to the pointer through small gearwheels. That's why, the value of a previous
measurement is seldom precisely the same as when the measurment is retaken. The best thing to do, is to take several measurements and then by addition and division, calculate the average value.
The dial indicator gauge is unsuitable for absolute measuring statements. It merely shows the differences between two measuring situations. For this reason, it also has a calibration ring which can be turned to every
point on the scale. This then indicates the starting value. 11/09