Ultrasonic flowmeter features
The unique signal digitization processing technology makes the meter measurement signal more stable, anti-interference ability and more accurate measurement.
No mechanical transmission parts are not easily damaged, maintenance-free and have a long service life.
The circuit is more optimized, with high integration, low power consumption and high reliability.
Intelligent standard signal output, friendly man-machine interface, multiple secondary signal output, for you to choose.
Pipe-section small pipe diameter measurement is economical and convenient, and the measurement accuracy is high.
Detailed installation of ultrasonic flowmeter
Ultrasonic flowmeters should be aware of the site prior to installation, including:
1. What is the distance from the host at the installation of the sensor;
2. Pipe material, pipe wall thickness and pipe diameter;
3. Years of pipeline;
4. The type of fluid, whether it contains impurities, bubbles and whether it is full;
5. Fluid temperature;
6. Whether there is interference source at the installation site (such as frequency conversion, strong magnetic field, etc.);
7. Four seasons temperature at the host place;
8. Whether the power supply voltage used is stable;
9. Do you need remote signals and types;
According to the site conditions provided above, the manufacturer can configure the site conditions and, if necessary, special models.
Vortex flowmeter analysis and solution
3. Reasons for parameter setting direction. The instrument is incorrectly indicated due to a parameter error. The parameter error makes the secondary meter full frequency calculation error, and the reason for this is mainly related to questions 1 and 3. The full-scale frequency is similar, indicating that the long-term inaccuracy is indicated. The full-scale frequency of the actual full-scale frequency and large-dry calculation indicates that the range is fluctuating and cannot be read. The inconsistency of the parameters on the data affects the final determination of the parameters, and finally passes. Recalibration combined with mutual comparison to determine the parameters solves this problem.
4. The secondary instrument is faulty. There are many faults in this part, including: when the instrument board is disconnected, the range setting has individual bit display bad, and the K coefficient setting has individual bit display bad, which makes it impossible to determine the range setting and K factor setting. Part of the reason is mainly related to questions 1, 2. The problem is solved by fixing the corresponding fault.
5, Four-way line connection problem. On the surface of some circuits, the line connection is very good. Check carefully. Some connectors are actually loose and the circuit is interrupted. Some connectors are tightly connected, but the fastening screws are fastened to the wire due to the secondary line problem. Interruption, this part of the reason is mainly related to question.
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.
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.