Abstract
    In the industry control history, the pressure vessel fluid positionsurvey is occupying the very important role. Speaks of the fluidposition survey, can let the person remember the industry to controlthe scene each kind of reaction vessel. Because the pressure vesselfluid position cannot directly carry on the survey, must be able toobtain the fluid position altitude through the sensor switchingcircuit the electrical signal. The present paper was the monolithicintegrated circuit AT89S5 2 monolithic integrated circuits whichproduced based on ATMEL Corporation is a core, through the plateMAX187typeelectric capacity sensor principle, transformed the fluid positionchange the plate capacitor electric capacity change quantity survey,referred to the electric capacity the introduction, caused the fluidposition density the change not to be able to affect the fluidposition altitude the survey. Will recuperate the electrical signalfrom the plateMAX187type electric capacity sensor signal which the electriccircuit will obtain, will send in monolithic integrated circuitAT89S52 to carry on the correlation processing. The monolithicintegrated circuit will examine the fluid position informationtransmits through the RS485 main line for PC machine, in the PCmachine end, use configuration software (configuration king) the fluidposition   information which transmits to the monolithic integratedcircuit carries on the dynamic demonstration. After the synthesistest, this installment has the certain use value

     Keywords:Pressure vessel;PlateMAX187type electric capacity sensor; RS485;Kingview