Gas Sensor Bulk Test System Based On MSP430 SCM

Along with social progress and the strengthening of people's environmental awareness, the attention and investment of state and government to the field of environmental monitoring become larger and larger, the further enhance to detection and control of variety of toxic and hazardous, flammable and explosive gas. So gas sensors are widely used in variety of industrial sites, as well as in life, however, in the process of gas sensor development and production, low testing efficiency and accuracy, the characteristics and parameters of gas sensor can not be real-time monitoring, these factors limit the mass production and application of gas sensors.Connection with the need of topic research and practical application in this paper, the gas sensor bulk test system,which is based on MSP430 single chip as control and process core is designed in this paper. The achievement of data acquisition and processing with VB6.0 is expatiated. The system is capable of testing an eight-channel gas sensor once and drawing real-time responding characteristic curve of gas sensor. It achieves the high-performance testing of performance parameters of the gas sensor. The main research tasks of this topic are as follows:1. Front-end processing circuit design. Mainly through the voltage regulator chip, integrated operational amplifier, a programmable constant current source which is voltage-current mode is designed. When the current of constant current source flows through the gas sensor, the resistance signal of the sensor can turn into standard-voltage acquisition signal. Because of the large scope of gas sensor resistance changing, may be to the megohm, a series range of the signal attenuation are designed to ensure that the voltage between 0 ~ 3V.2. The design of the core of slave machine in the test system. The core of the data acquisition part is the MSP430F149 MCU with 12-bit AD, it turn the 0 ~ 3V external voltage signal into a digital quantity, then revert to the actual analog quantity through software conversion, and send to the PC processing.3.The PC software design in the test system. The core of PC monitor and control is PC and the monitoring software written in VB. The main function is constituted by data reception, storage, real-time drawing and sending commands to control the acquisition of a single or multi-channel, and so on.The development of this system, effective solving the accurate detection of the gas sensor performance parameters, providing a complete parameter information for the sensor users and researchers, providing reference method and system architecture for developing similar test system. The system not only provides the necessary testing tools for manufacturers, promotes China's industrialization process of gas sensor, but also provides a powerful means for carrying out the reliability research of gas sensor.