Research And Development Of Carbon Monoxide Alarm Sensitivity Testing System

Carbon monoxide alarms have become increasingly popular. CO alarms for residential use is an important choice of life safety. Many countries around the world have published national standards for residential CO alarms, so it has a high demand on the performance testing of CO alarms. With the title “Research and Development of Carbon monoxide alarm sensitivity testing system ", the thesis was based on linear interpolation method and Lab VIEW virtual instrument technology to design a testing system for carbon monoxide alarm sensitivity test and run experiments to verify the system reliability. It have practical significance.According to national and international standard test methods and requirements, and linear interpolation method based on LabVIEW virtual instruments, using the infrared gas Analyzer and programmable controller design based on experience data interpolation, and precisely control the test gas concentration detection system. Main tasks are as follows:(1) Study and summarize test method and requirement of popular national standards for residential carbon monoxide alarms, and identify the test system development methods and specifications.(2) According to the standard requirements, Design the system scheme of carbon monoxide alarm sensitivity testing system, and the system consist of four main parts: PC and PC base software, gas analyzers, gas injection device and test chamber.(3) Research equipment requirement in measurement precision, range, method of operation of gas analyzer, as well as research data communication via RS-485 port between the PC and infrared gas analyzers.(4) Learn LabVIEW method of interpolation function; design user interface and communication programs between PC and the infrared gas analyzer and Panasonic PLC in Mewtocol protocol and gas injection control program.Finally the test system was verified by experiment and meet the standards requirement in controlling accuracy, gas injection time in different gas concentration. The tolerance of test gas less than±3% and the gas injection time less than 50 seconds. The test system met the standards requirement and the laboratory testing requirements under actual use in past one year.