Design And Research Of Multi-variable Transmitter

In recent years, people have paid much more attention to the accuracy of flow measurement as technology progresses. But the volume fluid measurement can not meet the requirements for the industrial development any longer. In mixture and quality control of industry, material and energy balance as well as commerce storage, what we need is mass flow measurement. So multi-variable transmitter has research and industrial value.The Multi-variable transmitter was developed on base of V type internal cone throttling set. It integrated temperature and pressure sensor with V-Cone flow sensor, and it realized the accurate measurement of mass flow through the compensation of steam density.The multi-variable transmitter used the MCU which named MSP430 as the main controller. During the period of measurement, the system used differential pressures signal which was obtained by V type internal cone throttling set as the main signal, used the absolute pressures signal and the temperatures signal as the compensation signal to calculate the steam mass flow. The transduction circuits transform the differential pressures, the absolute pressures and the temperatures received by the sensors into the voltage signals, and then, the voltage signals are transformed into digital signals by the A/D converter. The MCU processes these digital signals and calculates the mass flow with the temperature and pressure compensation mathematical model of saturated steam and superheated steam. Furthermore, we added some methods of anti-interference in software and hardware design.Using V type internal cone throttling set as the measurement front of multi-variable transmitter could overcome the defects of traditional throttling set such that the measuring precision is low and the pressure loss is tremendous. It has a widely developing space.