9 Scientific, optical, measuring, signalling, checking apparatus and instruments, namely, for monitoring and controlling the flow of gases, liquids and fuel, and for monitoring and controlling combustion, power generation and turbine efficiency; surveying instruments and apparatus; weighing instruments and apparatus; computer-controlled electric apparatus for use in controlling turbines, generators and heat pumps; observation, monitoring, regulation, measuring, testing and quality control apparatus for use in connection with turbines and boilers, namely, flow meters, fluid or gas flow measurement apparatus, fuel consumption meters, combustion monitoring apparatus, air, gas or liquid level indicators, air, gas or liquid level meters, automatic valves for monitoring or controlling air, gas or liquid levels, power controllers; pressure control and pressure relief valves for gas and air; electric installations for the remote control of industrial operations, namely, for controlling of drivers and motors; frequency meters; gas testing instruments; pressure indicators; pressure measuring apparatus; structural parts and fittings for all the aforesaid goods; apparatus and instruments for conducting, switching, transforming, accumulating, regulating or controlling electricity, namely electric control panels, electric switches, electric sensors for vibration, temperature, pressure and compressed air flow, level measuring gauges, power controllers, and electric ignition controls