Test Apparatus for Measuring Sound Power Levels of Drills

This Bureau of Mines report describes in detail the design and operation of a test apparatus for measuring the sound power levels of drills used by the mining industry. The two major components of the test apparatus are a computer-controlled automated drill test fixture (adtf) and a 45,000-ft3 reverberation chamber that houses the adtf. Design specifications and performance capabilities of the adtf and the reverberation room are given. Initial test results for three types of drills - a pneumatic percussion drill, a hydraulic percussion drill, and a pneumatic rotary drill - are given to illustrate the types of experiments that can be conducted with the test apparatus.