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.
Ultrasonic flowmeter common problems (2)
5, the external clip type ultrasonic flowmeter signal is low?
This depends on the technical content of the instrument itself. After a large number of test cases on the spot, it proves that the long-term pipeline, serious scaling and large diameter, the Aitulel AFTU-2W series is better than other external-clip ultrasonic flowmeters. The signal is very fast and the signal is very stable. .
Solution: For large diameter and serious scaling, it is recommended to use a good quality external clamp type ultrasonic flowmeter. The pipe at the probe installation should be cleaned, and the air between the probe and the workpiece surface should be removed with a coupling agent or coupling piece to make the ultrasonic wave. It can be effectively introduced into the pipeline to ensure sufficient sound intensity transmission on the detection surface.
6. Occasionally, there are bubbles in the measurement medium. Does the ultrasonic flowmeter with the time difference method have any influence?
Today's Aitulel AFTU-2W series external clip type ultrasonic flowmeter has dual mode. When there is air bubble, it can be automatically transferred to Doppler mode to measure. When the bubble disappears, it will automatically turn into the time difference method.
7. The meter cannot be used under strong interference on the spot?
On-site inverter or high voltage cable field strong electromagnetic interference
Recommendation: Keep away from the inverter or high voltage cable field electromagnetic interference
8. What is the minimum diameter of the externally clamped ultrasonic flowmeter on the market? What is the highest temperature?
Answer: Now only the minimum diameter of the AFTU-2W series in the world can be measured to 6mm, the temperature can be measured at 550 °C, such as the measurement of molten salt and heat transfer oil, which is not possible with other brands of flowmeters. of.
9. How to choose a suitable ultrasonic flowmeter?
Answer: Pipe material, pipe wall thickness and pipe diameter; fluid type, contain impurities, air bubbles and full pipe; fluid temperature, flow meter type, portable or fixed online.
Turbine Flowmeter Product Introduction
A flow meter that uses a turbine for measurement. It first converts the flow rate to the speed of the turbine and then converts the speed into an electrical signal proportional to the flow. This flow meter is used to detect instantaneous flow and total integrated flow, and its output signal is frequency, which is easy to digitize. In the figure, the induction coil and the permanent magnet are fixed together on the casing. When the ferromagnetic turbine blade passes the magnet, the magnetic resistance of the magnetic circuit changes to generate an induced signal. The signal is amplified and shaped by an amplifier and sent to a counter or frequency meter to display the total integrated flow. At the same time, the pulse frequency is frequency-voltage converted to indicate the instantaneous flow rate. The speed of the impeller is proportional to the flow rate, and the number of revolutions of the impeller is proportional to the total amount flowing. The output of the turbine flow meter is a frequency modulated signal that not only improves the immunity of the detection circuit, but also simplifies the flow detection system. It has a turndown ratio of 10:1 and an accuracy of ±0.2%. Turbine flowmeters with small inertia and small size have a time constant of 0.01 seconds.
Turbine flowmeter is the main type of velocity flowmeter. When the fluid to be measured flows through the turbine flowmeter sensor, under the action of the fluid, the impeller is forced to rotate, and its rotational speed is proportional to the average flow velocity of the pipeline. At the same time, the blade periodicity The magnetic flux generated by the electromagnet is cut and the magnetic flux of the coil is changed. According to the principle of electromagnetic induction, a pulsating potential signal, that is, an electric pulse signal, is generated in the coil, and the frequency of the electric pulsation signal is proportional to the flow rate of the fluid to be measured.