Smart Composite Vacuum Gauges

Because science progresses unremittingly , the technique of vacuum applies increasingly and extensively, and the significance of vacuum measurement becomes more and more important. Meterage in the vacuum is subjected to restriction of sensors, the measuring rang is narrow when only a single sensor is used. For enlarging the measuring rang, we can spread 2 kinds or 2 kinds above the sensor compound usage, and realize the intelligent switching among sensors, thus we can use one set compound vacuometer to account the vacuum that can immediately carry out big scope to measure.Compound vacuometer must be able to realize intelligent switching among sensors, and intelligent switching among different ranges of one sensor in the measuring progress. The measure scope of one sensor usually crosses over 3-5 pieces to measure class. Under the different amount class, the work parameter of the sensor is different. In order to promise the measuring accuracy the vacuometer must be able to adjust the work parameter of the sensor under the different amount class in good time.This system compounds the ZJ — 53 B thermocouple gauge which is used for low vacuum measuring and the ZJ— 10 ionization gauge which is used for median vacuum measuring, and realizes the intelligent control. The thermocouple gauge used in this system is obviously non-linear. For raising measure accuracy, we must improve nonlinearity. This thesis passes comparison argument, chose to use thrice spline interpolation method. After analysis and validation, we know that this method is suitable for improving nonlinearity, and satisfy the measure accuracy in vacuum measuring, so it have a certain expansion application value.This system uses Freescale's MC9S12 series 16 bit single-chip computer as the center controller for intelligent control. The low electric signal that is outputted from the sensor is put into the single-chip computer after magnifying and A/D conversion. Then through range conversion and non-linear correction, scale transformation, the signal will be displayed as figures. And through the msCAN12 module embedded in the MC9S12, data can be transmitted to the CAN bus, realizing real time communication with other...