Combining with the actual， from the specific characteristics of three-dimensional garage， combining with the teaching demonstration， the characteristics of the tool design the teaching with three-dimensional garage， choose lifting and transferring parking of the basic structure， operation process using PLC for the automatic
Water content in crude oil is an important parameter of oil industry in the process of mining， smelting and transporting， so the precision of oil's water content is of significance for confirming the oil's quality and definite interest of both sides of trade Oil一water mixture has two state: water in oil emulsion (low water content under 30%) and oil in water emulsion(high water content up 30%)Now the factories only can measure high water content online in china， but have no precise online low water content measuring A majority of those precise online low water content measuring instruments are imported from Canada and other foreign Measurement of oil's low water content (0%一10%) is based on the theory of measuring oil's dielectric constant with the differential charge transferring method in this The effect of stray capacitance and resistance on accuracy is reduced How the wax deposit and the variety of oil sample and temperature affect measurement is also Temperature shifting is solved through temperature compensation with triple spline For the problem of wax deposit after long time use， it is revised with one point of It is convenient for workers' The instrument use MSP430 Flash low power MCU and LCD in So this instrument need very low This instrument also can communicate with PC through RS It is convenient for supervising and data And it has 4一20mA current Key words: differential charge transfer; oil’s water content; low power; dielectric constant
