Level meter concept classification

Level meter concept classification

 What is the classification of the level meter concept? What are the classifications, Xi'an Huaheng Instrument introduces you: the basic concept, the level refers to the amount of material relative to a certain reference, is the general term for liquid level, material level and phase boundary.

(1) Liquid level. The relative height of the liquid level stored in various containers or the relative height of the surface of the liquid in the rivers, rivers, lakes, seas and reservoirs in nature.
(2) Material level. The relative height or surface position of solid particles, powders, etc. stored in containers, yards, warehouses, etc.
(3) Phase interface position. The interface position between two media of different density but incompatible with each other stored in the same container. Usually refers to the liquid-liquid phase interface, liquid-solid phase interface.

The measurement of the level refers to the measurement of the above three positions, and the results are usually expressed in absolute length units or percentages. The meter for measuring the solid level is called the level gauge, the meter for measuring the level is called the level gauge, and the meter for measuring the position of the interface is called the interface meter. According to the series of level measuring instruments produced in China and the actual application of the factory, the liquid level measurement occupies a considerable proportion. Therefore, the liquid level measuring instruments commonly used in factories are mainly introduced here, and the principle is also suitable for other level measurement.

Classification of level measuring instruments:

There are many methods for measuring the level, and the measuring range is wide, ranging from a millimeter to a few tens of meters, or even higher, and the production process requires different levels of material measurement. Therefore, there are many types of level measuring instruments used in the industry, and the working principle can be divided into:

(1) Direct reading level measuring instrument. It uses the principle of the connected device to directly display the liquid level in the container through a glass tube or a glass plate that communicates with the container to be tested. It is the most primitive but still widely used level gauge.
(2) Static pressure gauge measuring instrument. It is a meter that indirectly measures the level by using liquid school or material accumulation to generate pressure on a certain point, measuring the point pressure or measuring the pressure difference between the point and another reference point. This type of instrument has three types: pressure gauge level gauge, differential pressure level gauge and blown liquid level gauge.

(3) Buoyancy level measuring instrument. This is based on the principle of force balance, which uses a position that floats on a type of suspended matter to change with the change of the liquid surface to reflect the liquid. It is divided into three types: float type, float type and lever float type. They both measure the liquid level and the latter two also measure the liquid-liquid phase interface.
(4) Electrical level measuring instrument. It is a meter that converts the change of the level into a change in the amount of electricity and performs an indirect measurement of the level. According to the different power parameters, it can be divided into three types: capacitive, resistive and inductive. Inductive can only measure the liquid level.
(5) Acoustic level measuring instrument. The level is detected by the propagation speed of the ultrasonic waves in the medium and the reflection characteristics between the interfaces of the different phases. It can be divided into three types: air-mediated, liquid-media and solid-media. Among them, air-based can measure liquid level and material level; liquid-based can measure liquid level and liquid-liquid phase interface; solid medium can only measure Liquid level, such as: ultrasonic level gauge
(6) Optical level measuring instrument. It uses the principle of the level of the interception and reflection of light waves to measure the level. There is a laser level gauge that can measure liquid level and material level:
(7) Nuclear radiation level measuring instrument. When the radiation emitted by the radioisotope passes through the measured medium. Absorbed and weakened, the degree of attenuation is related to the thickness (level) of the measured medium. Non-contact detection of liquid level and level can be achieved by this method.

In addition, there are three types of mechanical level measuring instruments: heavy hammer type, tuning fork type and rotary type, as well as microwave type, thermoelectric type, weighing type, explosion-proof type ultrasonic level gauge, jet type and the like. New principles and new varieties are still evolving. The level measuring instrument can be divided into continuous measurement and position measurement according to the different functions of the instrument. The former can realize continuous measurement, control, indication, recording, remote transmission, adjustment, etc. of the material level. The latter is relatively simple and inexpensive, and is mainly used for fixed-point alarms and automatic systems for automatically entering and leaving materials.

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