The Research Of Portable Sulfured Hydrogen Tester Based On MSP430

With our country development of the economy, the various chemical and hazardous articles'production, store, transport and use are increasing gradually. The poisonous goods was divulging to pollution of the environment now and again in recent years. And have brought heavy losses to society economy and the people life and property.The sulfureted hydrogen is nerve poisonous with the smelly egg smell. Also it is a suffocating and stimulating air. The main effect target of the sulfured hydrogen's toxicity is the central nervous system and the breath systems. The target and toxic reason of acute toxicosis of sulfured hydrogen will be different with contact time and the sulfureted hydrogen strength. The higher strength will be more restraining on the central nervous system, the lower strength will be more stimulate velum. If a long time exposing in sulfured hydrogen, it will be tremendous injury to human body, the heavy even lead to death. With people taking more and more attention to environmental protection, so the measure of the sulfureted hydrogen seems to be very important, also it has very big market demand.There are many method of measure sulfureted hydrogen now. But there are many disadvantages with them. For example, the silver nitrate compares the color method that has the law insensitive disadvantage. And some other methods have short stability.Now the dissertation will introduce portable sulfured hydrogen Tester Based on MSP430 that use the electrical current electrochemistry sensor. The electrical current electrochemistry sensor has the high sensitive and veracity .Also it has the small volume, easy to operate, easy to take and low price disadvantages. It can be used in spot monitor .So it has be used in many air tester and has occupied important position in detecting air market. The sensor can detect wide air range. the main applied realm contain safe examination, the environment monitor and other special uses.The electric current signal coming out from the hydrogen sulfide sensor changes into tiny voltage signal by the course sensor work circuit. The tiny voltage signal change into the 0 to 2.5 voltage by the amplify circuit, and then change the analog signals to digital signal by ADC module. The MSP430 deal with the digital signal and show it on the LCD. The tester completes different functions by the key.The tester is based on MSP430.The MSP430 incorporates a 16-bit RISC CPU, peripherals, and a flexible clock system that interconnect using a von-Neumann common memory address bus and memory data bus. Partnering a modem CPU with modular memory-mapped analog and digital peripherals, the MSP430 offers solutions for demanding mixed-signal application. Its system has the advantage of good stability and high dependability.The software system designs four work sate to complete different function. The first state is to adjust the zero; the second state is to detect the sulfured hydrogen. The third and the last state are to set up the sample point. With regard to dependability of operation, adds the function of boot-strap with a button for the sake of avoiding the error of boot-strap. The design has some characteristics. For example, simple structure of circuit,convenience of operation,low power using up,stabilization of system.