Water level control refers to the control of high and low water levels by mechanical or electronic methods. It can control solenoid valves, water pumps, etc. to become an automatic water level controller or water level alarm, thereby realizing semi-automation or full automation.

Water level control is generally used for high-level tank water supply and sump drainage. The device that converts the water level signal into an electrical signal to control the start and stop of the water pump is called a water (liquid) level controller. Commonly used water (liquid) level controllers include reed switch water level controllers, float magnetic switch liquid level controllers, electrode type water level controllers, pressure type water level controllers, etc.

Water Level Control

Types of water level controllers

  • Floating ball controller
  • Reed water level controller
  • Cable water level controller
  • Electronic water level controller
  • Capacitive water level controller
  • Tuning fork water level controller
  • Electrode water level controller
  • Photoelectric water level controller

Water has buoyancy, and the float level controller is manufactured according to the buoyancy of the liquid. When the liquid level rises, the float system also rises accordingly. When the liquid level decreases, it also decreases accordingly.

When ascending or descending to the set position, the float system will hit the controller at the set position. This will cause the controller to issue an electrical signal.

The electronic control equipment will act immediately when it receives an electrical signal, cut off or connect the power supply, and constitute an automatic control system.

Extended reading: Float Level Sensors – Single and Multipoint

Reed water level controller is suitable for automatic control or alarm of water level in water towers, water tanks, pools, etc. in industrial and mining enterprises, civil buildings, and scientific and technological research fields. At the same time, it can also be widely used in the “three wastes” disposal facilities for environmental protection.

There are one or several buoys on the cable water level controller that move with the water level. A permanent magnetic ring is fixed in the buoy. When the buoy moves to the upper or lower water level, the corresponding reed switch will accept the magnetic signal and act to send out the water level electrical signal. . Used to alarm or start the pump to work.

Extended reading: Hydrostatic Level Measurement

The electronic water level controller detects the water level through the built-in electronic probe. Then the chip processes the detected signal. When it is judged that there is water, the chip outputs a high level of 24V or 5V, etc. When it is judged that there is no water, the chip outputs 0V .

The concave-convex level signal is read by PLC or other control circuit boards, and drives the electrical appliances such as water pumps.

It can be installed in any direction. When installed horizontally, it will act when the water level reaches the blue line, and the precision is high. When installed vertically, it will act when the water level reaches the red line, which has a certain anti-wave function.

The capacitive water level controller changes according to the small capacitance difference caused by the detection of the water level change. It uses a special ADA capacitance detection chip for signal processing. It can output a variety of signal communication protocols.

Capacitive water level detection can detect the change of water level or liquid in the container through any medium. It avoids the disadvantages of poor stability and reliability of traditional water level detection methods.

The tuning fork on the tuning fork water level controller is excited by the crystal to generate vibration. When the tuning fork is immersed in liquid, the vibration frequency will change. This frequency change is detected by the electronic circuit and outputs a controller quantity.

Extended reading: Magnetic water meter-ultrasonic water meter-mechanical water meter

The electrode type water level controller is an integrated measurement system composed of a primary electrode type sensor and a secondary controller. The water level controller is installed on the top of the container or on the wall of the container, and the electrode is inserted into the liquid.

During measurement, there is an AC signal voltage on the electrodes. When the liquid level rises and touches the electrodes, there is a communication signal current flowing between the electrodes, and then a liquid level signal is generated. After the control board receives the liquid level signal, rectification, filtering, Expansion and other processing. Finally, it is converted into a relay closed contact output or a standard current 16mA output for users to use.

When the liquid level drops and leaves the electrodes, there is no communication signal current flowing between the electrodes. The control board cannot receive the liquid level signal, and the relay returns to the release state or the standard current returns to 8mA.

Therefore, the liquid level can be accurately measured through the contact or non-contact of the liquid and the electrode, the pull-in or non-attraction of the relay or the magnitude of the current.

The photoelectric water level controller uses infrared detection. It uses the principle of refraction and reflection of light. The light will reflect or refract at the interface of two different media.

When the measured liquid is at a high level, the measured liquid and the photoelectric controller form a kind of interface. When the measured liquid is at a low level, the air and the photoelectric controller constitute another interface. These two interfaces will make the photoelectric control The reflected light intensity received by the light-receiving crystal inside the device is different. That is, it corresponds to two different controller conditions.

Extended Reading: Procurement Guide for Ultrasonic liquid level sensors

Featured Water level Control and Sensors


A water level controller is a device that manages water levels on a variety of systems such as water tanks, pumps and swimming pools. The basic function of a water level controller is to regulate water flow and optimize system performance.

Extended reading: Radar Water Level Sensor Applied To River/Reservoir Monitoring

The water level controller is an instrument that can help users solve the waste of water resources. It can efficiently and timely solve the water cutoff and overflow conditions. More importantly, it can solve the problem of artificial water level control for users and realize automatic water level control.

The main functions of the water level controller are as follows:

  1. The display mode of the instrument: it has the functions of -1999~9999 measured value display and set value display, and can also display the working status of the light-emitting diode;
  2. Control mode: 1-4 limit control can be selected, LED indication. The control method is relay ON/OFF; with hysteresis (can be freely set by the user), the control accuracy is ±1 word, and the contact capacity: AC220V/3A, DC24V/6A resistive load.
  3. With alarm function: 1-4 limit alarm can be selected, LED indication. The alarm mode is relay ON/OFF; with hysteresis (user can freely set) alarm accuracy ±1 word, contact capacity: AC220V/3A, DC24V/6A resistive load.
  4. It can monitor the change of water level, according to the set upper and lower limit values ​​of water level and water level alarm value, it can automatically control the opening and closing of the water pump, and can output external alarm signals, which is convenient for users to take timely measures to deal with it.
  5. The instrument consists of three parts: sensor, transmitter and receiver. One transmitter can be configured with multiple receivers, and several receivers monitor the water level of the same water tower and pool at different locations. Provide users with more accurate water level information.

The water level controller has the characteristics of compact structure, economy, reliability, practicality, energy saving and consumption reduction. It is a new type of automatic control device worthy of promotion.

Extended reading: Float Switch Water Level Controller

The function of the liquid level sensor is to detect the liquid level. The liquid level sensor is widely used in electrical appliances and industrial equipment that require water level control. The liquid level sensor can realize the function of water shortage protection.

Principle of water level sensor:
The water level sensor has a sensor. Transform the sensed water level signal into a current signal.

There are many types of water level sensors, so their specific measurement principles are different.
If you need to learn more. You can refer to:
Differential pressure type liquid level measuring instrument;
Float level measuring instrument;
Electric liquid level measuring instrument;
Ultrasonic liquid level measuring instrument;
Radar liquid level measuring instruments, etc.

Extended reading: Capacitive water level sensor

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Sino-Inst offers over 20 Water Tank Level Sensors for Water Level Control.

About 50% of these are liquid level meters, 40% is the tank level sensor.

A wide variety of Water Tank Level Sensors options are available to you, such as free samples, paid samples.

Sino-Instrument is a globally recognized supplier and manufacturer of level measurement instrumentation, located in China.

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