MicroMotion科里奥利质量流量计原理试题.ppt

流量计系统部件 流量精度指标 典型精度计算 百分比精度举例 传感器精度曲线 调零步骤 用被测介质打循环约5分钟, 保证满管, 关闭流量计下游阀, 保证流量静止 用变送器上的调零按钮, 或375手操器对流量计进行调零 12/13/96 8 Introduction and Theory, Part II (= Transparency 26) The transmitter uses the temperature read from the RTD and the DTC factor to adjust the registered tube period for the effect of temperature on the tubes’ response. The transmitter uses the square of the tube period to eliminate the effect of the mass of the tubes themselves (see TX-145 in 1A.PPT). The function is fundamentally linear (as shown in TX-25), so the transmitter can use the slope-intercept method to determine the process density. The equation (again, for your information rather than for display) is: 12/13/96 31 Intro-1 (= Transparency 19) We need to know temperature to compensate for its affect on the elasticity and rigidity of the metal flow tubes, which determine how the tubes responds specifically to flow and density. We’ll discuss that again later. The temperature indicated by the RTD also represents the temperature of the process with considerable accuracy. In current Micro Motion sensor design, the RTD temperature is equivalent to a thermowell sensor in terms of indicating process temperature. 12/13/96 15 Introduction and Theory, Part II (=Transparency 31) Features of the D series: compatible with all transmitters (except 6-inch sensors, which are not compitible with the IFT9701). Only sensor series that can be used with the RFT9712. standard sensor available in sizes from .06-inch to 6-inch; flow ranges from 0-2 lb/min to 0-25,000 lb/min can be installed up to 1000 feet from transmitter available with high pressure fittings (except DS600) wetted parts 316Lstainless; also available with nickel alloy (with 304 stailess lap joing flanges); or lined with Tefzel (1.5- and 3-inch only) high pressure (DH) and high temperature (DT) models also available in several sizes single-tube, self-draining loop sensor (DL) for sanitary process applications or shear-sensitive fluids is availab