System to protect optics against dirty environments

摘要

An optical sensor head has deep, pitched grooves or screw threads in the walls of the gas channel, and a gas flow swirled along the grooves to protect optics against atmospheric debris and moving particles such as is generated by an industrial process. The grooves are pitched to support swirling motion of the gas. Use of swirled flow increases allowable flow velocity and diverts incoming particles toward the channel walls. The windows of an optical profiler, for instance, are protected against the smoke and weld spatter created by a metal-inert-gas welding torch.