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.
ltrasonic flowmeter installation
The time difference ultrasonic flowmeter is a competitive flow measurement method in the world today, and its measurement line accuracy is higher than 1.0%. Due to the diversity of the industrial site, especially the environment around the pipeline, how to install and debug the ultrasonic flowmeter according to the specific environment has become an important topic in the field of ultrasonic flow measurement. This procedure explains the installation details of the ultrasonic flowmeter; It further fully demonstrates the advantages of accuracy, reliability and stability of the ultrasonic flowmeter, greatly reducing future maintenance work and even maintenance-free.
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. Year of the pipeline;
4. 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. The temperature of the four seasons at the host site;
8. Whether the power supply voltage used is stable;
9. Whether remote signals and types are required;
According to the site conditions provided above, the manufacturer can configure the site conditions and, if necessary, special models.
The installation position and installation method of the ultrasonic flowmeter.
Selecting the installation pipe segment has a great influence on the test accuracy. The selected pipe segment should avoid the interference and eddy current, which have great influence on the measurement accuracy. Generally, the pipe segment should meet the following conditions:
1. Avoid installing the machine in the pump, high-power radio, frequency conversion, that is, where there is strong magnetic field and vibration interference;
2. Select the pipe section where the pipe should be uniform and dense, and it is easy to transmit ultrasonic waves;
3, to have a long straight pipe section, the upstream straight pipe section of the installation point must be greater than 10D (Note: D = diameter), downstream is greater than 5D;
4, the installation point upstream distance pump should have a distance of 30D;
5. The fluid should be filled with pipes;
6. There should be enough space around the pipeline to facilitate the operation of the on-site personnel. The underground pipeline needs to be a test well. The test well is as follows:
Ultrasonic flowmeters generally have two types of probe installation methods, namely Z method and V method.
However, when D < 200mm and the site condition is one of the following conditions, it can also be installed by the Z method:
1. When the measured fluid has high turbidity, when the V method is used to measure the signal or the signal is weak;
2. When the inner wall of the pipe is lined;
3. When the service life of the pipeline is too long and the inner wall is fouled seriously;
For those with better pipeline conditions, even if D is slightly larger than 200mm, in order to improve the measurement accuracy, the V method can be used for installation.