Method for measurement of shearing length of extension arm in movement beam in supporting device for e.g. supporting working tool in mobile crane, involves determining distance between communication units based on running time of signal

摘要

The method involves transmitting of a signal i.e. impulse, from a communication unit (21) to another communication unit (20) via a transmission medium i.e. air. Another signal i.e. ultra sound signals (30), is transmitted from the former communication unit to latter communication unit via another transmission medium in dependent upon the former signal. A distance between the two communication units are determined based on running time of the latter signal. Energy supply of the communication units are implemented via a controller-area networkbus. An independent claim is also included for a device for measurement of the length of the tubular element.