Intrinsically safe certified for use in hazardous areas. 4-20mA current loop output pressure transmitters for use on landfill sites where an area of land that is used to bury waste material.
Due to the decomposition of buried waste material over time, a landfill site presents a potential hazard to the environment unless precautions are taken to contain pollutants and prevent contamination.
Decomposing waste will produce a mixture of flammable and greenhouse house gases that can escape into the local atmosphere. In a landfill site extraction wells are used to collect the landfill gas (LFG) from surround waste at multiple locations around the site. This LFG is then treated and typically used to fuel power generators to provide electricity.
Pressure transmitters are measurement devices which combine an amplified 4 to 20 milliamp current loop output signal conditioning electronic module with a transducer for measuring the pressure of a liquid, vapour or gas.
Intrinsically safe certification is a standard used to limit the amount of energy, heat or ignition sources entering a hazardous zone which may contain a potentially flammable or explosive atmosphere.
Typically a pressure transmitter installed in a hazardous area is connected to other measurement instrumentation via a zener diode or galvanic (transformer) isolated barrier system located in a safe area.
The pressure transmitter is matched with the barrier system so that the barrier will prevent any voltage and current levels exceeding limits defined in the pressure transmitter intrinsic safety approval parameters.
Any electrical energy exceeding the barrier limits will be redirected to ground/earth in the case of the zener barrier or blocked in the case of the galvanic (transformer) isolated barrier.
Intrinsically safe certification is controlled and regulated by a government’s health and safety department in the country where the pressure transmitter is to be installed and used. Commercial organisations are appointed to provide assessment and approval services to industry.