Electromagnetic flowmeter features
Frequency programmable low frequency rectangular wave excitation improves stability of flow measurement and low power loss.
The new 16-bit ultra-low power microprocessor with FLASH memory has high integration, fast calculation speed and high calculation accuracy.
Full digital processing, strong anti-interference ability and reliable measurement.
Ultra-low EMI switching power supply, suitable for power supply voltage variation range, high efficiency, small temperature rise; good EMC performance.
Chinese and English menu operation, easy to use, easy to operate, easy to learn and understand.
High definition backlight wide temperature LCD display.
It can perform bidirectional flow measurement and bidirectional total accumulation; it has automatic range switching function, which can effectively improve the measurement accuracy of analog current and frequency output, especially suitable for occasions where the diurnal flow range changes greatly and needs to send control signals; flow measurement range Up to 1500:1.
There are three totalizers inside, which record and display the forward cumulative amount, the reverse cumulative amount and the accumulated difference integrated amount, which are convenient for fluid metering and custody transfer.
Provide isolated or non-isolated RS485/RS232C digital communication interface, and support fieldbus communication modes such as MODBUS, PROFIBUS-DP and HART.
Constant current source fluid resistance measurement can accurately measure the internal resistance of the electrode signal in the case of long-line transmission. It can be used not only to determine whether the fluid in the sensor is empty or not, but also to identify abnormal phenomena such as contamination and coverage of the electrode, and to provide cleaning for the user. Fault processing information such as electrodes.
The ultrasonic flowmeter is designed based on the geometrical principle that the velocity of the ultrasonic wave propagating in the flowing medium is equal to the average flow velocity of the measured medium and the velocity of the acoustic wave itself. It is also measured by the flow rate to reflect the flow rate. Although the ultrasonic flowmeter appeared only in the 1970s, it is very popular because it can be made into a non-contact type and can be connected to the ultrasonic water level gauge for opening flow measurement without disturbing or resisting the fluid. There are promising flow meters.
Ultrasonic Doppler flowmeters fabricated using the Doppler effect have received widespread attention in recent years and are considered to be ideal gauges for non-contact measurement of two-phase flow.
Fluid oscillating flowmeter
The fluid oscillating flowmeter is designed based on the principle that the fluid will oscillate when flowing under specific flow conditions, and the frequency of the oscillation is proportional to the flow velocity. When the flow cross section is constant, the flow rate is proportional to the flow volume of the pilot volume. Therefore, the flow rate can be measured by measuring the oscillation frequency. This flowmeter was developed and developed in the 1970s. Because it combines the advantages of non-rotating components and pulsed digital output, it has a promising future. At present, typical products include vortex flowmeters and spiral vortex flowmeters.
The V-cone flowmeter is a new generation of differential pressure flow measuring instrument. In practical use, many factors have a great influence on the measurement accuracy of the differential pressure flowmeter, which increases the measurement error and reduces the accuracy.
The specific performance is as follows:
1) the design parameters are inconsistent with the working parameters;
2) there is no temperature compensation or compensation is incorrect;
3) the length of the upper and lower straight pipes is insufficient;
4) the cones and pipes are not concentric;
5) the pressure pipes Blockage, etc.
After on-site inspection, the shortage of straight pipe sections, disagreement, and blockage of the pressure guiding pipe can be ruled out.
The differential pressure transmitter is removed for verification, the transmitter is qualified, and the error is within the allowable range.
The technicians recalled the trend record of DCS preservation, and looked at the steam temperature and pressure recording curve. The temperature was between 120 °C and 150 °C, the pressure was between 0.3MPa and 0.6MPa, and the measured temperature and pressure deviated from the design value. The design parameter was temperature. 193 ° C, pressure 1.13 MPa). At the same time, the DCS configuration was viewed and it was found that there was no temperature and pressure compensation for the steam flow in the configuration.