An instrument for measuring abrasive water jet diameter

In order to improve the accuracy of abrasive water jet (AWJ) machining the precise value of the jet diameter has to be known. Because of an aggressive environment caused by high velocity abrasive grains, the diameter is not easily measured. That is why a measuring device consisting of a load cell and a wear resistant probe was developed. The device measures the force of the jet while it passes over the edge of the probe. If the feed rate of the jet is constant and the time needed for jet to pass is known, the diameter can be determined. Because of probe wear issue several preliminary tests were made with water jet only in order to determine the measuring uncertainty and accuracy of the device. In the end the measurement of the AWJ was performed for two different focusing nozzles of different diameters. (C) 2009 Elsevier Ltd. All rights reserved.