Checking and control apparatus for vacuum pumps and vacuum pump stands, namely, Control valves for regulating the flow of gases and liquids, Power controllers, Leak detectors for vacuum pumps; vacuum, measuring and testing apparatus, namely, vacuum gauges, Laser measuring systems, Voltage testers; leak detection apparatus, namely, leak detectors for vacuum pumps; residual gas analyzers; gas measuring apparatus, namely, gas sensors for measuring gas concentration; vacuum-tight, mechanical and ...