Design of data acquisition and processing system of photoionization signal based on C8051F040

In this paper, a new kind of data acquisition and processing system of portable photoionization detect instrument is introduced. Using the fully integrated mixed signal chip C8051F040 as the micro control unit, this system can realize functions of the double range measurement of the data acquisition, the temperature compensation, the digital display and the serial interface for data sending. The design of double range measurement circuit and the design of the temperature compensation circuit are described in detail. This system has many advantages, such as high integration, small in size, low power dissipation, easy operation and wide application scope, etc.