How it works:
Electromagnetic water meter: Based on Faraday’s law of electromagnetic induction, when the conductive fluid passes through the applied magnetic field, it will cut the magnetic inductance line to generate induced electromotive force, and determine the velocity of the measured medium by measuring the strength of the electromotive force, and then obtain the flow value. The measuring tube needs to have a certain conductivity of the measured water.
Ultrasonic water meter: By detecting the time difference caused by the change of speed when the ultrasonic beam propagates in the water upstream and upstream, the flow rate of water is obtained by analyzing and processing, so as to further calculate the flow rate of water.
Measurement performance:
Measurement accuracy:
Both can achieve high measurement accuracy, and usually can meet the requirements of high precision scenarios such as trade settlement. However, in specific applications, the measurement accuracy of electromagnetic water meters is relatively more stable at medium and high flow rates; The ultrasonic water meter can also maintain good measurement accuracy at low flow rate.
Range ratio:
The measuring range of the electromagnetic water meter is higher than usual, and some products can reach 1:400 or even higher, which can adapt to the larger flow range. The range ratio of ultrasonic water meters is also relatively excellent, generally better than 100:1, and it has better performance in the measurement of large flow and small flow.
Equipment characteristics:
Wear property:
There are no mechanical moving parts inside the electromagnetic water meter and ultrasonic water meter, and there is no mechanical wear problem, so the accuracy has little relationship with the use time, and the general verification cycle is longer.
Pressure loss:
There is no blocking structure inside the electromagnetic water meter, and the water flow can pass smoothly with minimal pressure loss; The ultrasonic water meter also has the characteristics of small pressure loss, meeting the minimum level of pressure loss δp10.
Protection level:
Both, as electronic products, have higher requirements for protection levels, and generally need to reach ip68 to adapt to a variety of complex use environments.
Installation requirements:
Straight pipe section requirements:
The requirements for the straight pipe section of the ultrasonic water meter are relatively loose, and the industry-leading products can be better than u3d0, that is, the upstream needs 3 times the pipe section aperture length, and the downstream can be directly connected to the bend pipe.
The requirements of the electromagnetic water meter are relatively high, generally u10d5 or u5d3, that is, the upstream needs 10 times or 5 times the pipe segment aperture length, and the downstream needs 5 times or 3 times the pipe segment aperture length.
Installation method:
Ultrasonic water meter installation is flexible, can be horizontal, vertical or inclined installation; Electromagnetic water meters can usually only be installed horizontally or vertically, and the electrodes must be in the same horizontal plane.
Power supply and endurance:
Power supply demand:
Electromagnetic water meter is based on the principle of electromagnetic induction, the power consumption is relatively large, generally requires 15s to measure a flow.
The ultrasonic water meter has low power consumption and relatively short measurement cycle.
Battery life:
The battery life of the electromagnetic water meter is generally 3-5 years; The battery life of the ultrasonic water meter can reach 6-10 years under the current measurement cycle of at least 1s.
Anti-interference:
Electromagnetic water meter: The amplitude of the electrode signal generated by the sensor in its converter is weak, the signal is susceptible to changes in the magnetic field, and the anti-electromagnetic interference performance is relatively poor.
Ultrasonic water meter: When the transducer sends and receives ultrasonic signals, once there are bubbles in the water, which will affect the normal measurement, the anti-bubble interference ability is relatively weak.
Cost:
In general, at the same level of function and performance, the price of ultrasonic water meters will be higher than that of electromagnetic water meters. However, from the perspective of long-term use and maintenance costs, the overall cost of ultrasonic water meters may be more advantageous due to factors such as small maintenance workload and long service life
Post time: Nov-05-2024