Research And Design Of The Intelligent Dangerous Gas Detector System

Intelligent gas detecting instruments, especially the hand held instruments have played more and more important role, as the requirement of the manufactory field safety purpose.First of all, this paper describes the history, sort, and characteristic of intelligent instrument. And then, it turns to focus on the gas detector and introduces its feature and direction in the future. During hand held gas detecting instrument design, network design, multi-gas function, intrinsic safety specification and low power is considered as the key issues. Among the four points, the intrinsic safety and low power specification will be introduced in this paper. They will also be the difficulty points.Based on MSP430F449 microcontroller, this paper gives out a detail understanding of each module, including each hardware and software components, to achieve a design of hand held CO gas detector. Especially, it is focus on the instrument intrinsic safety and low power issue.In intrinsic safety part, the current spark and thermal effect is the main point. This design can ensure that in any situation, the energy in circuit will not exceed the limitation of explosion level, which is defined in GB3836.4.For low power purpose, the target is to achieve the both 2-year using with one cell, by the co-work of hardware and software. On the hardware side, picking up low power electrical units and MCU should be carefully considered. And from the software point of view, switching to low speed crystal in sleep mode is a good way to reduce the consumption. Shutting off the supply for some electrical module is also a good way to expend battery life time. Finally, the battery can reach 20000 hours working time to meet the requirement of 2 years working on 3.6V/2200mA Li-SOCl2.