| 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-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 instrument. A majority of those precise online low water content measuring instruments are imported from Canada and other foreign countries. Measurement of oil's low water content (0%-10%) is based on the theory of measuring oil's dielectric constant with the differential charge transferring method in this paper. The effect of stray capacitance and resistance on accuracy is reduced greatly. How the wax deposit and the variety of oil sample and temperature affect measurement is also studied. Temperature shifting is solved through temperature compensation with triple spline interpolation. For the problem of wax deposit after long time use, it is revised with one point of measurement. It is convenient for workers' operation.The instrument use MSP430 Flash low power MCU and LCD in hardware. So this instrument need very low power. This instrument also can communicate with PC through RS485. It is convenient for supervising and data processing. And it has 4-20mA current output. |
PDF Full Text Request