In-Line Gas Detection System

This issue analyzes and summarizes the domestic and foreign development situation of gas monitor, and developed a gas-line monitoring system, the system consists of upper and lower machine composed of two parts. PC by the computer monitoring software and communication interface component, lower machine by the portable gas detector and communication sub-stations.PC software is implemented on the attendance of Members of gas detection, and the gas concentration and temperature monitoring and alarm, and report printing this information, staff can also check the software to record historical data, using RS-485 bus and lower machine remote communications, the monitoring software uses advanced visualization to write programming language Visual Basic.Lower machine using AT89C2051 as portable gas detector and communication sub-station microprocessor. Portable Gas Detector mainly by the microprocessor, the temperature detection circuit, the gas concentration detection circuit, V/F conversion circuit, display circuit, infrared communication circuit, power circuit and alarm output circuit form. Among them, the gas concentration was determined by LXK-3 catalytic element sensor, the temperature was measured with digital temperature sensor DS18B20, mainly to complete the gas concentration, temperature, test, and pass the data communication sub-station. Mainly by the microprocessor sub-station communication, infrared communication circuit, RS-485 communication circuit and communication indicating circuit power supply circuit, power circuit directions and instructions and multi-voltage analog switches, etc., and mainly for data transmission, and portable gas detection instrument for infrared communication with the host computer RS-485 communications, the portable gas detector collected data passed to host computer. Infrared communication circuit is TSAL6200 and TSOP1838 infrared transceiver module as, RS-485 communication circuit is MAX1480 RS-485 level as a conversion chip.The system is on-site use, works well, stable and reliable, to achieve the design objective to achieve the detection of gas concentration and gas monitors attendance.