APPARATUS AND METHOD FOR MEASURING THE LENGTH OF A PIPE WITH USE OF MULITI FREQUENCY SIGNALS

摘要

PURPOSE: A piping length-measuring device is provided to improve the measurement accuracy of pipe length by removing the noise of particular frequency band. CONSTITUTION: A piping length-measuring device comprises pipelines(3a,3b), a multi-distance detecting signal transmitting part(120), and a multi-distance detecting signal receiving part(220). The piping interlinks one or more outdoor units(110) and an indoor unit(210). The multi-distance detecting signal transmitting part is combined in the piping of the outdoor unit. The multi-frequency distance sensing signal is transmitted through the piping.