For equipment allowing both positive and negative application of moment loads, a respective loading principle is shown in the following picture.


Loading principle for tilting clearance measurement

The first measurement should be performed when the equipment is put into operation in order to obtain a base value for subsequent repeat measurements.

The measuring points should be marked around the circumference while the boom is kept in a specified position.

The measurements are then taken between the lower mating structure and the bearing bolted to the superstructure:



The measurements should be taken as close to the bearing as possible in order to minimize the effect of elastic deformations in the system.

The dial gauges should have an accuracy of 0.01 mm. Start with applying the maximum backward moment and set the dial gauges to zero. Then apply a forward tilting moment, with load uptake, if necessary.

Turn the superstructure to the next position and repeat the measurement procedure.

When all positions have been measured, record the base values obtained in tabular form:

Measurement		Base measurement	Test measurement	Test measurement
Measuring point 1 below	boom
	counterweight

The measurements should be repeated every twelve months as a minimum and under identical conditions as the base measurement.

The difference between the values measured and the base values represents the wear that has occurred.

If the wear is found to have heavily increased, the time intervals between measurements should be shortened.

If the acceptable wear values are exceeded, please consult Rothe Erde.