Selection Of Measurement Methods For Liquid Level Gauges

There are only a few ways to measure liquid level in industry: 1. Input type; 2. Ultrasonic; 3. Radar; 4. Pressure change type.
Each of the above forms has its own advantages:
1. Let’s talk about the drop-in type first. As the name suggests, it is to put the sensor probe into the middle of the liquid, and use the pressure of the liquid to measure the depth of the liquid. The advantage is that it is in direct contact with the liquid, and the price is relatively cheap. The disadvantage is that when the liquid is a highly corrosive medium or a medium with a high viscosity, the drop-in type is not very suitable.
2. Ultrasonic liquid level gauge is to use the principle of ultrasonic transmission and reception to measure the depth of liquid without contact. The propagation speed of ultrasonic waves is relatively constant at a certain temperature. When the speed is known, as long as the time from sending out to receiving ultrasonic waves is calculated, the distance from the ultrasonic probe to the liquid surface can be calculated. The depth of the pool or the height of the tank is fixed, and the distance from the liquid level to the probe is calculated, and the distance from the liquid level to the bottom of the pool or the bottom of the tank is also calculated, that is, the depth of the liquid. Its advantage is non-contact measurement, which is relatively hygienic and can detect highly corrosive media. The disadvantage is that the generation and reception of ultrasonic waves has relatively high requirements on the environment. In the case of relatively harsh environments, ultrasonic liquid level gauges are not very applicable.
3. The radar liquid level gauge uses the emission and reception of microwave pulses to measure the depth of the liquid. The radar liquid level gauge has two forms: contact type and non-contact type. The emission of microwaves does not require a medium, so it can also be measured in a vacuum. In addition, radar can be used in very harsh environments, which is much wider than ultrasonic waves.
4. The pressure variable liquid level is mainly used on the tank body, and its installation methods include threaded installation and flange installation. There are also open and closed jars. In this way, it is divided into single flange liquid level and double flange liquid level. Its scope of use is relatively narrow.