Apparatus for testing gas, liquids and solids; Automatic valves for controlling the flow of oil in pipelines; Automotive measuring instruments, namely, water temperature gauges, air fuel/ratio gauges, boost gauges, vacuum gauges and exhaust gas temperature gauges; Diesel oil emission testers; Electronic apparatus for testing automobile engine oil; Electronic valves for controlling gas or fluids; Flue gas analyzers; Gas detectors for detecting the presence of gas; Gas sensors for measuring gas...