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Description of the use conditions of the electromagnetic flowmeter

The electromagnetic flowmeter is a speed meter with high precision, good repeatability, convenient installation and use. Suitable for clean or basic clean pipeline pressures in petroleum, chemical, city gas, metallurgy, mining and other industries relative to constant gas and single phase gases such as natural gas, propane, butane, ethylene, nitrogen, air, etc. The electromagnetic flowmeter is measured using a turbine. 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. The induction coil and the permanent magnet are fixed together on the housing. 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 electromagnetic flowmeter is a frequency modulated signal, which not only improves the anti-interference 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%. The electromagnetic flowmeter with small inertia and small size has a time constant of 0.01 second.
The working principle of the electromagnetic flowmeter: the measured gas entering the instrument; it is rectified and accelerated under the action of the special structure B-type rectifier. Because the turbine blade and the fluid flow direction are at a certain angle, the rotational torque is generated under the action of the fluid. Under certain conditions, The angle of rotation of the turbine is proportional to the volume of the fluid. The rotation of the turbine is driven by a worm, a magnetic connector, and a deceleration system to drive a mechanical counter to display the volumetric capacity of the gas to be measured.
Electromagnetic flowmeter features:
1. With B-type rectifier with unique structure, the requirements of straight pipe sections before and after the instrument are low (pre>>3DN, after>=1DN);
2. Self-lubricating roller bearing, easy to use and maintain;
3. Adopt mechanical display, no power supply, no explosion-proof requirements;
4. Short-term overload 1.2Qmax, the instrument is not damaged;
5. Small pressure loss and strong anti-interference ability;
The electromagnetic flowmeter is used correctly: the running condition of the flowmeter must be checked frequently, the maintenance work should be done, and the problem should be eliminated in time.
1. Before the electromagnetic flowmeter is put into operation, the meter factor should be set first. Check carefully to make sure that the flowmeter is connected correctly and the grounding is good before sending power.
2. Regularly clean, inspect and re-calibrate the flowmeter. The flowmeter with lubricating oil or cleaning fluid injection port should be filled with lubricating oil or cleaning fluid regularly according to the requirements of the manual to maintain good operation of the impeller.
3. The inspection shows the status of the instrument, and the evaluation shows the reading of the meter. If there is an abnormality, it should be checked in time.
4. Keep the filter unblocked. The filter is blocked by impurities, and it can be judged from the increase of the difference of the pressure gauge reading at the inlet and the outlet, and the blockage is promptly eliminated, otherwise the flow will be seriously reduced.
5. For large-flow trade settlement measurement, in order to ensure the accuracy of the flowmeter, the flowmeter must be checked frequently. The site should be equipped with on-line calibration equipment or equipped with a mobile calibration device. Although the one-time investment is large, it is worth considering from the long-term economic benefits.
Conditions of Use:
1. Environmental conditions Ambient temperature: -30 ° C ~ 55 ° C Relative humidity: 5% ~ 95%
Medium temperature: -30 ° C ~ 80 ° C atmospheric pressure: 96Kpa ~ 10Kpa
2. Fluid condition: The measured fluid should be a single-phase gas, and the flow rate and pressure range of the measured fluid should be within the specified range.

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