Machinery testers generally check that parts fit and move correctly and are properly lubricated, check the pressure of gases and the level of liquids, test the flow of electricity, and do a test run to check for proper operation. Senior inspectors may also set up tests and test equipment. Inspectors, testers, and graders are involved at every stage of the production process. Some inspectors examine materials received from a supplier before sending them to the production line. Others inspect components, subassemblies, and assemblies or perform a final check on the finished product.
Inspectors mark, tag, or note problems.
They may reject defective items outright, send them for rework, or, in the case of minor problems, fix them themselves. If the product checks out, they may screw on a nameplate, tag it, stamp a serial number, or certify it in some other way. Inspectors, testers, and graders record the results of their inspections, compute the percentage of defects and other statistical parameters, prepare inspection and test reports, notify supervisors of problems, and help analyze and correct problems in the production process. They also calibrate precision instruments used in inspection work. The recent emphasis on quality control in manufacturing has meant that inspection is becoming more fully integrated into the production process.