Liquid level sensor (static pressure liquid level gauge / liquid level transmitter / liquid level sensor / water level sensor) is a pressure sensor for measuring liquid level. Static pressure input liquid level transmitter (liquid level gauge) is based on the principle that the measured liquid static pressure is proportional to the height of the liquid, and adopts foreign advanced isolated diffused silicon sensing element or ceramic capacitor pressure sensing sensor to convert the static pressure into electrical signal, and then into standard electrical signal (generally 4 ~ 20mA / 1 ~ 5VDC) after temperature compensation and linear correction.

Liquid level sensors can also be divided into several types?

It is divided into two categories: one is contact type, including single flange static pressure / double flange differential pressure liquid level transmitter, floating ball liquid level transmitter, magnetic liquid level transmitter, input liquid level transmitter, electric inner floating ball liquid level transmitter, electric float liquid level transmitter, capacitive liquid level transmitter, magnetostrictive liquid level transmitter, servo liquid level transmitter, etc. The second type is non-contact type, which is divided into ultrasonic liquid level transmitter, radar liquid level transmitter, etc.

Liquid Level Sensor

Static pressure input liquid level transmitter (liquid level gauge) it is suitable for liquid level measurement of various media in petrochemical, metallurgical, electric power, pharmaceutical, water supply and drainage, environmental protection and other systems and industries. Its exquisite structure, simple adjustment and flexible installation mode provide convenience for users to use easily. Standard signal output modes such as 4 ~ 20mA, 0 ~ 5V and 0 ~ 10mA are optional by users according to their needs. Using the principle of hydrostatics Measuring liquid level is an important application of pressure sensor. The special cable with ventilation duct in the middle and special sealing technology are adopted, which not only ensures the water tightness of the sensor, but also connects the reference pressure chamber with the ambient pressure, so as to ensure the high precision and high stability of the measurement.

Working Principle

Principle of static pressure measurement: when the liquid level transmitter is put into a certain depth of the measured liquid, the pressure on the liquid level of the sensor is as follows: Ρ = ρ . g. H + Po, where:

P: Pressure on liquid level of transmitter

ρ： Measured liquid density

g: Local gravitational acceleration

Po: atmospheric pressure above the liquid level

H: Depth of liquid into the transmitter

At the same time, the pressure of the liquid is introduced into the positive pressure chamber of the sensor through the air guide stainless steel, and then the atmospheric pressure Po on the liquid level is connected with the negative pressure chamber of the sensor to offset the Po on the back of the sensor. Make the pressure measured by the sensor: ρ . g. H, obviously, the liquid level depth can be obtained by measuring the pressure P.

Functional features

◆ good stability, the long-term stability of full degree and zero position can reach 0.1% FS / year. The temperature drift is lower than 0.1% FS in the compensation temperature range of 0 ~ 70 ℃, and lower than 0.3% FS in the whole allowable working temperature range.

◆ it has reverse protection and current limiting protection circuits. During installation, the positive and negative poles are reversed, which will not damage the transmitter. In case of abnormality, the transmitter will automatically limit the current within 35mA.

◆ solid structure, no movable parts, high reliability and long service life.

◆ convenient installation, simple structure, economy and durability.

Main technical parameters

Process: diffusion silicon ceramic capacitor sapphire capacitor optional. Split type, integrated type, optional, measuring range: 0 --- 0.5 --- 200m, output: 4 --- 20mA (2-wire system), power supply: 7.5 --- 36VDC, 24vdccbm-2100 / cbm-2700 input static pressure liquid level gauge is recommended, which is reliable, anti-corrosion and equipped with ceramic measuring unit, and is used for level measurement of purified water, sewage and brine. Gy500 input split type liquid level transmitter adopts diffused silicon piezoresistive core, 316 all stainless steel structure, and the shell adopts isolated explosion-proof design. The input type liquid level gauge is mainly suitable for liquid level measurement and control of rivers, groundwater levels, reservoirs, water towers and containers. The circuit adopts signal isolation and amplification, frequency cut-off interference Design (strong anti-interference ability, lightning protection), overvoltage protection, current limiting protection, impact resistance, anti-corrosion, etc.] main technical parameters: b] measuring medium: water, oil and other liquid pressure types: gauge pressure, absolute pressure (no default gauge pressure is required)]

b] Range: 0 ~ 300m intermediate range optional comprehensive accuracy: 0.1% FS output signal: 4 ~ 20mA (two-wire system), 0 ~ 5V, 1 ~ 5V 0 ~ 10V (three wire system) power supply voltage: 12 ~ 36VDC medium temperature: - 30 ~ 60 ℃ ambient temperature: - 40 ~ 85 ℃ zero temperature drift: ≤± 0.05% FS ℃ range temperature drift: ≤± 0.05% FS ℃ compensation temperature: 0 ~ 70 ℃ safety overload: 150% FS limit overload: 200% FS sampling frequency: ≤ 2ms load capacity: (current type) 250 ~ 1425 Ω (voltage type) ≥ 2K Ω sealing grade: IP68 long term stability performance: 0.1% FS / year vibration impact: within the mechanical vibration frequency of 20Hz ~ 1000Hz, the output change is less than 0.1% FS mechanical connection (threaded interface): input type (submerged)] product size (mm): b]

Put the split liquid level transmitter into operation

⊙ high precision and isolated sensitive components imported from the United States are selected, with reliable performance
⊙ gauge pressure or absolute pressure measurement
⊙ range width: 1mh2o ~ 200mh2o
⊙ output: 4 ~ 20mA or 0 ~ 5V
⊙ power supply voltage: 24VDC (12 ~ 36VDC), MV output type is constant current 1.5madc or constant voltage 12VDC
⊙ high precision, better than 0.2% F.S
⊙ 100% waterproof and moisture-proof, protection grade IP68
⊙ complete circuit function, convenient adjustment

What is the working principle of fbelec non-contact liquid level sensor?

The distance between the sensor and the measured object is calculated by the time of transmitting and receiving the signal. Since the propagation speed in the air is certain and the distance between the liquid level sensor and the bottom of the container is certain, the liquid level of the measured object can be known.

Liquid level sensor is a pressure sensor for measuring liquid level. Static pressure input liquid level transmitter (liquid level gauge) is based on the principle that the measured liquid static pressure is proportional to the height of the liquid.

Adopt foreign advanced isolated diffused silicon sensor or ceramic capacitor pressure sensor to convert static pressure into electrical signal, and then convert it into standard electrical signal (generally 4 ~ 20mA / 1 ~ 5VDC) through temperature compensation and linear correction.