Design And Implement Of Testing System Based On Non-dispersive Infrared Gas Sensor

In the verification process of new quantitative detection and analysis model of non-dispersive infrared gas absorption, the effect of the environment temperature and pressure should be considered. This Paper designed a small experimental testing system, which with adjustable temperature and pressure. The testing system is used to simulate the ambient temperature and pressure conditions, and verify new detection model.The design goals, the function and technical specifications are described in detail in the paper. In the overall structure, the hardware circuit, software program and the corresponding mechanical components are designed. In the hardware circuit, power circuit, the design of the microcontroller and processing circuit, liquid crystal display, keyboard scan, an acousto-optic alarm,temperature control and data acquisition circuit, pressure control and data acquisition circuit, serial interface communication circuit is described in detail. Using one-wire digital temperature sensor DS18B20 as signal acquisition chip; absolute pressure sensor MPX4250 as a pressure signal acquisition chip. As semiconductor chip cooling temperature control equipment; using micro-pump as pressure control equipment.In software design to Keil C51 compiler environment as a software development platform, the system is divided into the following tasks:system initialization tasks, liquid crystal display task, keyboard scan task, temperature control and data acquisition circuit task, pressure control and data acquisition circuit task,etc.In mechanical components,the design of an airtight insulation and pneumatic mechanically tunable test case is described.Experiments show that the paper system designed to meet the needs of the experiment.