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Ultrasonic level gauge principle and related technical questions and answers

First, the principle Ultrasonic level gauge consists of ultrasonic sensors and electronic transmitter units. The sensor is mounted on the upper part of the container, and under the control of the electronic unit, the sensor emits a pulse of ultrasonic waves to the object to be measured. The sound waves are reflected by the surface of the object and are converted by the sensor into electrical signals. From the time the ultrasonic wave is transmitted to the time it is received again, its time is proportional to the distance from the sensor to the object being measured. The electronic unit detects the time and calculates the measured distance based on the known speed of sound. The level value can be obtained by the operation of the CPU.

Second, technical questions and answers 1. What kind of application environment is the ultrasonic level meter suitable for? It is usually applied to the measurement of liquid level or level at a temperature between -40 ° C and 95 ° C and a pressure below 3 Bar (5 kg / cm 2 ). In the case of normal temperature and normal pressure, it is the best choice to select the ultrasonic level gauge to measure the liquid level. It has the characteristics of reliable operation, simple installation, long service life and maintenance-free, and has a relative price advantage. Since the ultrasonic level gauge does not contact the measured medium when measuring the level, and is a fully enclosed anti-corrosion structure, it is most effective for liquid level measurement of various liquids such as viscous, corrosive, and turbid.

2. What should you pay attention to when measuring the level of volatile liquids in a closed container? There are two points to note: a The speed of sound in the container may be different from the speed of sound in the air. If the level gauge cannot correct the speed of sound, a certain error will occur. b The volatile liquid will condense on the surface of the ultrasonic level gauge probe. Blocking the transmission and reception of sound waves requires the level gauge to have variable power control. Our products meet the above requirements and have a large number of practical applications.
3. What is the effect of the ultrasonic level gauge on the solid level? It is feasible to use the ultrasonic level gauge for level measurement, and there are enough application experience and successful examples. When measuring the material level, the installation position should be selected to select the position where the material surface is relatively flat; for the powder level, the level meter with larger power (range) can be selected for measurement.

4. How do you use an ultrasonic level gauge for liquid level measurement for liquids with sharp liquid levels? There are three possible ways: a Use an ultrasonic level gauge with automatic power control b Use a larger range of ultrasonic level gauges c Add a plastic tube to the liquid and measure the liquid level in the plastic tube

5. Is the two-wire ultrasonic level gauge different from the three-wire ultrasonic level gauge? The two-wire ultrasonic level meter has a circuit shared by the power supply (DC24v) and the signal output (DC4-20mA). Only two lines can be used. It is a standard transmitter form. The disadvantage is that the transmit power is relatively slightly weak. . The three-wire ultrasonic level meter is actually a four-wire system. The power supply (DC24v) is separated from the signal output (DC4-20mA) circuit. Each line uses two lines. When their negative ends are connected in common, three lines are usually used. . The advantage is that the transmission power is large.

6. What is the blind spot of the ultrasonic level gauge? When the ultrasonic level meter emits an ultrasonic pulse, the reflected echo cannot be detected at the same time. Since the transmitted ultrasonic pulse has a certain time width, and the sensor still has residual vibration after the ultrasonic wave is emitted, the reflected echo cannot be detected during the period, so a small distance from the probe surface downward cannot be detected normally, and the distance is called a blind zone. If the highest level being measured enters the blind spot, the meter will not be detected correctly and an error will occur. If necessary, you can increase the level gauge installation.

7. Ultrasonic level gauge is a general term for ultrasonic level gauge and ultrasonic level gauge. When used to measure liquid levels, it is often referred to as an ultrasonic level gauge. When used to measure solids levels, it is often referred to as an ultrasonic level gauge.

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