Research On New Technology Of Malodorous Gas Detection System With Wide Concentration Range

With the development of our country's economy,environmental problems have become increasingly prominent.The odour pollution brought huge influence to people's life.However,due to the development of the research on odour pollution in our country,there is no significant effect at present.Therefore,developing a malodorous gas detection device which can truly reflect the status of environment pollution,has important practical significance.Based on the weak signal detection technology,this paper explores the method of effective detection of malodorous gas.Making the instrument technology used in the detection of the malodorous gas as the main research object,developed an electronic nose device which is based on a multi-sensor array and can realize the detection of a wide concentration range of malodorous gas.The paper presents a system design framework of the free combined sensor array,and designs the corresponding sampling pool.The basic idea of the design are as follows: choose the corresponding sensor for malodorous gas with different types and concentrations,and strive to enable the sensor to fully respond to sample gas in the sampling pool.In the aspect of circuit,using the 24 bit high resolution ADC chip to sample.With 128 times programmable gain in the chip,can simplify the peripheral circuit,and realize accurate detection of large concentration of gas at the same time.This thesis completed the design of the system according to the above design concept.In addition,the scheme development of the equipment,component selection,circuit design,air route design and software design and so on were described in detail.And at the end of the paper,the preliminary test of the system is finished.Through experimental verification,the equipment designed and developed in this project has been able to work properly.And it has the advantages of high precision and good stability.In particular,the system design framework of the free combined sensor array which has a certain reference value and application prospects provides great flexibility for the system to adjust according to the actual needs of the environment.