The working principle, advantages and disadvantages of bundled ultrasonic flowmeter
Advantage：1, because it is tied on the outer side of the pipe, the fluid in the pipeline is not damaged, the process flow is not affected, and the assembly can be disassembled at any time;2, because the bundle in the pipe outside, there is no pressure problems;3, no contact medium, ignore medium corrosion, measuring medium range;4, compared with large diameter pipe type flowmeter, the price is much cheaper;Shortcoming:1, can not withstand high temperatures, generally not higher than 160 degrees;2, small caliber (DN15 or less) can not be installed measurement;3, the relative and the pipe section type and insertion type ultrasonic flowmeter, the signal passes through the pipeline wall, the precision and the signal strength, and the quality of pipe material, installation standard or not have a relationship, errors will be more.
The working principle of bundled ultrasonic flowmeter (also called external clip type ultrasonic flowmeter):Generally used time difference method, Doppler method is now rarely used. That is: when the ultrasonic beam propagation in the liquid, due to fluid flow, the ultrasonic propagation time in positive and negative direction of a slight difference, this time difference is proportional to the micro propagation of liquid flow, and thus the measured fluid flow.
First of all, correction, you said the flow meter industry, known as the external clamp type ultrasonic flowmeter, not called binding type. The measuring principle of the ultrasonic time difference method, the simple point is the installation of two sensors in the outer wall of the pipeline, simultaneously transmitting and receiving acoustic signals, because one is a downstream, upstream, so have the time difference, this time difference is proportional to the flow rate of the fluid, the cross-sectional area are multiplied by the flow rate of the pipeline you can get traffic.Advantages: 1. Non-contact measurement, easy installation and maintenance, no process stop. 2, measuring medium range is relatively wide, 3, relative to other flowmeter, big diameter has price advantageDisadvantages: 1, poor precision, poor stability. Many manufacturers claim 1%R, or even higher 0.5%, but it is difficult to achieve such accuracy at the user's site. There are many factors that affect the accuracy and stability. For example, the straight pipe section is not enough, the pipe is fouling, the probe time is long and easy to be loose, etc. this shortcoming is also the fatal flaw of the ultrasonic wave. Therefore, the ultrasonic flowmeter is rarely used on occasions with high precision. 2, small diameter measurement effect is poor, the error is greater, generally speaking, DN15 below, domestic products simply can not measure. And there is no advantage in price.
