1. Measurements are not affected by changes in fluid density, viscosity, temperature, pressure, and conductivity;
2. There is no obstructed flow component in the measuring tube, no pressure loss, and the requirements of the straight pipe section are low. Unique adaptability to slurry measurement;
3. Reasonable selection of sensor lining and electrode materials, that is, good corrosion resistance and wear resistance;
4. The converter adopts novel excitation mode with low power consumption, stable zero point and high precision. The flow range can reach 150:1;
5. The converter can be integrated with the sensor or separated;
6. The converter adopts 16-bit high-performance microprocessor, 2x16LCD display, convenient parameter setting and reliable programming;
7. The flowmeter is a two-way measuring system with three totalizers: positive total, reverse total and total difference; can display positive and negative flow, and has multiple outputs: current, pulse, digital communication , HART;
8, the converter uses surface mount technology (SMT), with self-test and self-diagnosis function;
9. Measurement accuracy is not affected by changes in fluid density, viscosity, temperature, pressure and conductivity. The sensor induced voltage signal has a linear relationship with the average flow velocity, so the measurement accuracy is high.
10. There is no obstruction in the measuring pipe, so there is no additional pressure loss; there is no moving parts in the measuring pipe, so the life of the sensor is extremely long.
11. Since the induced voltage signal is formed in the entire space filled with the magnetic field and is the average value on the pipeline surface, the sensor requires a short straight pipe section and a pipe diameter of 5 times.
12. The converter adopts the latest and most advanced single-chip microcomputer (MCU) and surface mount technology (SMT) in the world. It has reliable performance, high precision, low power consumption, stable zero point and convenient parameter setting. Click on the Chinese display LCD to display the cumulative flow, instantaneous flow rate, flow rate, flow percentage, and more.
13, two-way measurement system, can measure forward flow, reverse flow. Special production technology and high-quality materials ensure that the performance of the product remains stable for a long time.
Vortex flowmeter verification detection method
Standard table method
The vortex flowmeter is used as a standard device in series with the flowmeter to be inspected, and can be verified by static method or dynamic method. By comparing the readings of the two flow meters, the error of the vortex flowmeter to be tested is obtained.
Standard table flow meter standard device features:
1. Standard table method is suitable for measuring various fluids (including liquids and gases), and also for liquids of various viscosities.
2. The indication value is checked. The flow meter used as the standard meter is installed in series with the flowmeter to be tested in the same closed pipeline system. Generally, there is no time measurement error.
3. As a standard table, the vortex flowmeter can be the same as or different from the flowmeter to be tested.
4. When the flow meter is verified by the standard meter method, the airflow or liquid flow can be not cut off, so it is suitable for online verification, and is also suitable for the measurement standard for the closed pipeline. 5, the standard table method is easy to achieve automation, sealed and safe, does not pollute the environment.
6. Small size, light weight, simple device structure, convenient operation, easy transportation and installation, and low cost.
7. Standard meter flowmeters have low accuracy and poor stability, and often need to be compared regularly or irregularly to monitor their metering performance. The standard table has a shorter verification period.
Several problems of solutions
Recalculating the differential pressure scale
Temperature and pressure compensation can only reduce the measurement error, not only can not solve the problem fundamentally, but also the measurement signal exceeds 20mA, resulting in steam leakage measurement. The transmitter measurement signal exceeds 20 mA, indicating that the actual measured differential pressure signal ΔP exceeds the design differential pressure value.
Increase temperature and pressure compensation
When the temperature and pressure of the steam change, the density of the steam changes, and the steam flow measurement produces an error. Measurement error can be reduced by temperature and pressure compensation. Since the temperature of the saturated steam is a single-valued function of the pressure, the temperature and pressure compensation of the saturated steam can be pressure compensated or temperature compensated. Because the pressure signal detection is sensitive and the compensation accuracy is high, it is compensated by pressure and realized by DCS.
Conclusion
Steam is a special medium. As the pressure and temperature change, the density of steam changes. Therefore, it is necessary to compensate for temperature and pressure. When the pressure and temperature fluctuation of the steam are not large, that is, when the operating condition parameters deviate from the design parameters and the influence on the measurement is small, the temperature and pressure compensation measures can achieve the purpose of accurate measurement. However, when the operating parameters deviate too much from the design parameters or the operating parameters fluctuate frequently and are too large, even with the temperature and pressure compensation, it is difficult to meet the measurement accuracy requirements. At this point, only differential pressure or flow can be recalculated for a particular throttling element.