Submersible liquid level sensor is a pressure sensor used for liquid level measurement. Based on the principle that the hydrostatic pressure of the measured liquid is proportional to the height of the liquid, it uses an isolated diffused silicon sensing element or a ceramic capacitive pressure sensing sensor to convert hydrostatic pressure into an electrical signal, and then, after temperature compensation and linear correction, converts it into a standard electrical signal. It is generally suitable for liquid level measurement of various media in systems and industries such as petrochemical, metallurgy, electric power, pharmaceutical, water supply and drainage, and environmental protection.

 Submersible liquid level transmitter is based on the principle that the hydrostatic pressure of the measured liquid is directly proportional to the height of the liquid, and uses the piezoresistive effect of a diffused silicon or ceramic sensing element to convert hydrostatic pressure into an electrical signal. After temperature compensation and linear calibration, it is converted into 4-20mADC standard current signal output. The sensor part of the submersible liquid level transmitter can be directly immersed in the liquid, and the transmitter part can be fixed with a flange or bracket, making installation and use extremely convenient.

Working principle

 Using the hydrostatic pressure measurement principle:

 When the liquid level transmitter is immersed to a certain depth in the liquid being measured, the pressure formula on the liquid-facing surface of the sensor is:Ρ=ρ.g.H + Po

Where:

P: pressure on the liquid-facing surface of the transmitter ρ: density of the measured liquid

g: local gravitational acceleration

Po: atmospheric pressure above the liquid surface

H: immersion depth of the transmitter in the liquid

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

3Main technical specifications

Measuring range:0.0～110m

Accuracy:0.1、0.2、0.5、1.0 class

Operating temperature:-20～80℃

Output signal: two-wire 4～20mADC、three-wire voltage output, 485 communication, HART protocol

Power supply voltage: standard 24VDC（12～36VDC）

Dead zone:≤±1.0%FS

Load capacity:0-600Ω

Relative humidity:≤85%

Protection rating:IP68

Explosion-proof marking:ExiaⅡCT4-7