This test is performed to ensure that there are no leaks in the piping, compressor, or other pressure containing parts of the package. All openings in the completed compressor package are plugged and the unit is pressurized with nitrogen to 350 psig.
[pdf] We have developed a laboratory-based, test bench robotic system that drives an active drill into concrete while simultaneously measuring these health-related exposures and productivity. The measurement methods follow guidelines from national and international standards.
[pdf] Highly energy saving Comparing to non-variable speed screw air compressor, its average saving rate can be up to 50%; Super air displacement, its frequency is variable from OHz to 300Hz and the air displacement can be increased by as much as 28%; High efficient motor (IPM), its efficiency is up to 94.5%, reaching the rating of IE4.
[pdf] 
