Plug-in ultrasonic flowmeter features
Programmable frequency low frequency rectangular wave excitation improves stability of flow measurement and low power loss;
Using 16-bit embedded microprocessor, the operation speed is fast and the precision is high;
Full digital processing, strong anti-interference ability, reliable measurement, high precision, flow measurement range up to 100:1;
Ultra-low EMI switching power supply, suitable for wide range of power supply voltage and good anti-EMC performance;
Full Chinese character menu operation, easy to use, easy to operate, easy to learn and understand;
High definition backlit LCD display;
It has two-way flow measurement and two-way total accumulation function, and the current and frequency have bidirectional output function;
There are three totalizers in the internal to display the forward cumulative amount, the reverse cumulative amount and the difference integrated amount;
With RS485 or RS232 digital communication signal output
It has a conductivity measurement function to determine whether the sensor is empty or not;
The constant current excitation current range is large, and can be used with different companies and different types of electromagnetic flow sensors;
With self-test and self-diagnosis function;
High reliability with SMD devices and surface mount (SMT) technology;
The internal design of the meter has a power-down clock that can record 16 power-down times.
To ensure the measurement accuracy of the electromagnetic flowmeter, proper installation is very important.
1. The transmitter should be installed in a dry and ventilated place indoors. Avoid installation in places where the ambient temperature is too high, should not be subject to strong vibration, try to avoid equipment with strong magnetic fields, such as large motors, transformers, etc. Avoid installation in corrosive gases. The installation location is easy to overhaul. This is the environmental condition to ensure the normal operation of the transmitter.
2. In order to ensure that the measuring tube of the transmitter is filled with the measured medium, the stacker is preferably installed vertically, and the flow direction is from bottom to top. Especially for liquid-solid two-phase flow, it must be installed vertically. If the site is only allowed to be installed horizontally, it must be ensured that the two electrodes are at the same level.
3. The transmitter should be equipped with valves and bypass at both ends.
4. The millivolt AC potential measured by the electrode of the electromagnetic flow transmitter is based on the liquid potential in the transmitter. In order to stabilize the liquid potential and maintain the potential of the transmitter and fluid to ensure stable measurement, the transmitter shell and the metal tube should have good grounding at both ends, and the converter housing should also be grounded. The grounding resistance should not be greater than 10 and cannot be shared with the grounding wire of other electrical equipment. If the transmitter housing is not guaranteed to be in good contact with the metal pipe, connect them with metal wires. Re-reliable grounding.
5. In order to avoid interference signals, the signal between the transmitter and the converter must be transmitted with shielded wires. It is not allowed to place the signal cable and power cable in parallel in the same cable. The length of the signal cable should generally not exceed 30 m.
6. converter installation site should avoid AC and DC strong magnetic field and vibration, ambient temperature is -20 to 50 ° C, does not contain corrosive gases, relative humidity is not more than 80%.
7. In order to avoid the influence of the flow rate on the relative measurement, the flow regulating valve should be placed downstream of the transmitter. For small-caliber transmitters, since the distance from the center of the electrode to the inlet end of the flowmeter is equivalent to several times the length of the diameter D, the upstream straight pipe may not be specified. However, for a flowmeter with a large diameter, generally there should be a straight pipe section of 5D or more in the upstream, and the downstream pipe section is generally not required.
Choice of protection level
The protection level of the electromagnetic flowmeter should be selected according to the actual situation. If the sensor is required to be installed below the ground and is often flooded, IP68 should be selected. If the sensor is installed above the ground, IP65 and IP67 should be selected. In any case, the display area of ??the electromagnetic flowmeter cannot be used with water or enter the water, which may cause damage to the electromagnetic flowmeter. As a chemical company, the workshop produces high humidity, but IP65 (IP65 is a water-proof type. The electromagnetic flowmeter sensor housing allows the faucet to spray water from the sensor in any direction of the sensor of the electromagnetic flowmeter. The pressure of the water spray is 30Kpa, the water output It is 12.5L/S and the distance is 3 meters.) The electromagnetic flowmeter of the protection grade fully meets the requirements of on-site measurement.
Choice of connection method
Electromagnetic flowmeters have threaded connections, flanged connections, clamps, etc. In the chemical industry, flange-connected electromagnetic flowmeters are generally used. The selection must be consistent with the process-flange engineering pressure and standards.