The liquid level sensor (static pressure liquid level meter/liquid level transmitter/liquid level sensor/water level sensor) is a pressure sensor that measures the liquid level.
Liquid level sensor wiring
The method of liquid level sensor wiring The liquid level sensor. Generally, the signal output is 4-20mA, 0-20mA, or voltage 0-5V, 1-5V, 0-10V.Three -line output of voltage.At present, many of them do not have 24VDC power supply. Most of them are 10V. Some transmitters with large power consumption. 10VDCs power supply cannot be driven. Then it can only be connected to the power supply 24VDC.In this way, there are four wiring terminals on the liquid level: power supply+, power supply-, feedback+and feedback-.The fourth-line wiring method of the liquid level sensor wiring: power supply+== power supply+; power supply- == power supply-; signal+== feedback+, signal-== feedback-.The current second-line control method of the liquid level sensor wiring: power supply+== power supply+; signal+== feedback+, power supply- == feedback-if not far, you only need to connect 24V voltage+,-, if you need to stay far, you need to stay far away.It is rumored to form a circuit, such as 24V+Pressure table+, pressure gauge-connect 4 to 20mA+, 4 to 20mA-connect 24V-, there may be terminals in the middle, look at the loop diagram.The voltage-type three-line wiring method of the liquid level sensor wiring: power+== power supply+; power- (signal-) == power supply-; signal+== feedback+, power- (signal-).
Dalm level sensor type
1. Floating ball -type hydraulic transmitter: consisting of magnetic floating balls, measuring catheters, signal units, electronic units, wiring boxes and installation parts.The proportion of the general magnetic floating ball is less than 0.5, and it can be drifted on the liquid surface and moves up and down along the measuring duct.There are measurement components in the catheter. It can convert the measured liquid level signal into a resistance signal that is proportional to the fluid level under external magnetic action and convert the electronic unit to 4-20mA or other standard signal output.This transmitter is a module circuit, which has the advantages of acid resistance, moisture -proof, shockproof, and corrosion. The inside of the circuit contains a constant current feedback circuit and internal protection circuit, which can make the maximum output not exceeding 28mA.The second instrument is not damaged.
2. Floch -type hydraulic transmitter: It is designed according to the principle of Archimede buoyancy principle.The float -type liquid level transmitter is used to measure the liquid level, boundary, or density of the liquid liquid.It can perform conventional settings through the on -site keys at work.The transmitter uses the measurement principle of liquid static pressure.It generally uses silicon pressure pressure measurement sensors to convert the measured pressure into electrical signals, and then compensate for amplifying circuit amplification and compensation circuits. Finally, it is output with a current of 4 ～ 20mA or 0 to 10mA.
Principles of liquid level sensor working principle
Use static pressure measurement principle: When the liquid level transmitter is put into a depth in the measured liquid, the pressure formula of the sensor welcoming the liquid surface is: ρ = ρ.h+PO formula: p: transmitterStrong pressure on the liquid surface: Direct density G: Local gravity acceleration PO: Atmospheric pressure H on the liquid surface H: The transmitter puts the depth of the liquid at the same time.Then connect the atmospheric PO on the liquid surface to the negative pressure cavity of the sensor to offset the PO on the back of the sensor, so that the sensor measures the pressure: ρ.h. Obviously, the liquid level depth can be obtained by measured the pressure PO.Functional characteristics: ◆ Good stability, long -term stability of fullness and zero -position can reach 0.1%FS/year.Within the compensation temperature of 0 to 70 ° C, the temperature drifting is lower than 0.1%FS, and the entire allowable operating temperature range is lower than 0.3%FS.◆ It has reverse protection and current -limiting protection circuits. When installation, the positive and negative pole will not damage the transmitter. When an abnormal, the delivery device will automatically limit the current within 35mA.◆ Solid -state structure, no mobilized parts, high reliability, and long service life.◆ Easy to install, simple structure, and durable.

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