SENSORS FOR FLAMMABLE VAPORS AND GASES.

The traditional methods of minimizing flammable vapor and gas concentrations are to operate the processes outdoors and to dilute dangerous concentrations with large quantities of air. A major objection to the air-dilution technique is that it wastes energy. Recently developed vapor and gas-sensing systems can be installed to monitor and prevent dangerous concentration. The sensors can trigger alarms or initiate process adjustments to eliminate a developing hazard. With automatic and accurate control, such systems can significantly reduce the amount of dilution air needed in a process. Flammable-vapor detectors are being used to reduce ventilation requirements in a variety of applications: printing presses, coating lines, paint storage containers, solvent-tank farms, pump and compressor stations, and aerosol-container-filling operations. The article discusses types of sensors commonly used for this type of application, sensor selection, location and outputs.