Liquid level float switch is a commonly used liquid level controller. For water Tank & Pump alarm and level control. Can be divided into Continuous Float Level Sensor and Point Level Float Switch.

Purchasing Guide for Liquid level float switches

Liquid level float switch are sensors with an electrical contact output at a specific liquid level. Floats with permanent magnets. Single or multi point level indicator. Can choose stainless steel or anti-corrosion material. It is suitable for exploratory testing of the limit of liquid in small containers (boxes, barrels, cylinders, etc.).

Sino-Inst offers a variety of Liquid level float switches for level measurement and control. If you have any questions, please contact our sales engineers.

Featured Liquid level float switches for sale

SI-U05 Cable Float Level Sensor & Swtich
SI-U02 Multi-Point Liquid Level Float Switch
SI-U03 Float Switch Water Level Controller
SI-U04 Magnetic Float Level Sensor-Reed Switch

Know more about Liquid Level Switch

Liquid level switch, also known as water level switch, liquid level sensor. As the name implies, it is a switch used to control the liquid level.

In terms of form, it is mainly divided into contact type and non-contact type.

Commonly used non-contact switches include capacitive liquid level switches, and contact float-type liquid level switches are the most widely used. Electrode liquid level switches, electronic liquid level switches, and capacitive liquid level switches can also be realized by contacting methods.

Continuous Float Level Sensor

The floating ball continuous level gauge uses the floating ball to move up and down with the liquid to trigger or release the reed switch in the tube, and output 4-20mA or other different standard models through circuit processing.

With multi-interface measurement, easy to install, and corrosion-resistant, it can meet most measurement needs. Suitable for various tanks and tank level measurement, optional on-site display.

Point Level Float Switch

The float level switch uses a magnetic float to rise or fall with the liquid level. The sensor detects the reed switch chip at the set position in the tube, and sends out a contact opening (closing) conversion signal.

One or more dry reed pipes are installed in the closed non-magnetic pipe. Then the pipe passes through one or more hollow floats with ring magnets inside. The rise or fall of the liquid will drive the floating ball to move up and down together. Then the reed tube in the non-magnetic tube will pull on or off, and then output a switch signal.

According to needs, one or more liquid level switch points can be set.

Whether it is Continuous Float Level Sensor or Point Level Float Switch, they all need to be in contact with the medium.

However, in some cases, we need to measure and control the liquid level without contacting the medium. Then we can consider the following liquid level sensors.

Extended reading: Magnetostrictive Hydraulic Cylinder Position Sensor

How does a liquid level float switch work ?

Liquid level float switches are liquid level controllers that use one maglev ball or multiple maglev balls to send out multi-point switch signals.
Reed pipes are installed at different heights in the guide rod. When the maglev ball floats up and down as the liquid level changes. The magnetic steel in the floating ball makes the reed pipe at the corresponding position in the guide rod pull on or off, and send out a switch signal.

Read more about: 7 Level Senors for Tank Level Measurement

Explosion proof float switch

The explosion-proof float level switch is also called the explosion-proof float level controller. It is a liquid level control instrument specially designed and manufactured for use in explosive environments. Explosion-proof type ExdⅡBT4; intrinsically safe type ExiaⅡCT6.

Principle of explosion-proof float level switch:

①The mechanical strength conditions of the enclosure. That is, the shell has enough strength to withstand the internal explosion pressure without damage. And it does not produce permanent deformation that affects the explosion-proof performance.

②Control the conditions of non-detonation in the gap of the joint. That is, the shell joint surface has a sufficiently small gap and a sufficiently long engagement length. Explosive products (hot flames or particles) inside will not escape the shell and ignite the explosive mixture in the surrounding environment.

The principle of intrinsically safe explosion-proof technology is to start with limiting energy and reliably limit the voltage and current in the circuit to an allowable range. In order to ensure that the electric spark and thermal effects generated by the instrument in normal operation or short-circuit and component damage, etc., will not cause dangerous gases that may exist around it. It is actually a low-power design technique.

Multi-level float switch

Multi level float switch is also called multi point level switch. Support 1-4 liquid level measurement switch point customization.

SI-U02 Multi Level Float Switch

Multi level float switch is a custom multi point float level sensor & switch. These versatile level switches are available in many materials. Like: Stainless Steel, Brass & Buna, PVC, Polypropylene or PTFE and can be ordered with an integrated temperature sensor. Use these multi-level float switches with a tank level alarm or liquid level control relay for a turnkey solution. Explosion-proof available.

Vertical liquid level float switch & horizontal liquid level float switch

Vertical liquid level float switch refers to the float level switch installed in the vertical direction. It is usually installed on the top of the tank through flanges or threads. Keep it vertical.

Horizontal liquid level float switch refers to a float level switch installed from the horizontal direction, or from the side.

Vertical liquid level float switch & horizontal liquid level float switch

Float switches for water tanks

In water treatment, the float level switch of the water tank is directly related to the safety and reliability of the entire process.

In a process, there are different types such as intermediate water tank, backwash water tank, produced water tank and waste liquid tank. The sizes of these boxes are different. The volume of the produced water and the original water tank may be larger.

In these water tanks, the water tank float level switch is used for related control. Different liquid level switches will have different actions. However, it is not necessary to have several level switches in a large water tank.

In the water tank, there are high and low level switches. The high level switch can detect if the water tank is full. If it is full, stop producing water. The low level switch is used to detect whether the water in the tank is sufficient. If there is not enough water, no more water can be sent out.


What is float level switch?

The float level switch is a kind of level switch. The float level switch uses magnetic force to operate. No mechanical connections. The operation is simple and reliable. When the float switch floats the measured medium, the float moves the main body. At the same time, the magnet on the other end of the float will control the magnet on the switch action lever.

What is a liquid level switch?

Liquid level switch, also known as water level switch, liquid level sensor. As the name implies, it is a switch used to control the liquid level.

How does a float level sensor work?

Float level sensor: Float level sensor is designed and produced based on the principle of buoyancy and static magnetic field. The position of a floating ball with a magnet (floating ball for short) in the measured medium is affected by buoyancy. The change of the liquid level causes the position of the magnetic float to change. The role of the magnet and sensor (reed switch) in the floating ball changes the number of components (such as fixed resistance) connected in series to the circuit. Thereby changing the electrical quantity of the instrument circuit system. That is, changes in the position of the magnetic float cause changes in the electrical quantity. The change of the electrical quantity is detected to reflect the liquid level in the container.
The float level sensor is installed on the top of the container through a connection flange. The float ball floats on the liquid surface according to the principle of discharging the liquid volume phase and so on. When the liquid level of the container changes, the float ball also moves up and down. The reed switch of the ball level gauge is magnetically attracted to change the position of the liquid level into an electrical signal. The actual position of the liquid is displayed digitally by the display instrument. The floating ball level gauge can achieve long-range detection and control of the liquid level.

How do I test a float switch with a MultiMeter?

Turn on the power of the multimeter and set the multimeter to the continuity test position. The test multimeter displays 1, indicating that the test leads are disconnected.
Place the pointer of the multimeter, one wire is gently placed on the wire-in end of the switch terminal, and the other wire is lightly placed on the wire-out end of the switch terminal. If the display is 0, it means that the two terminals are connected to the normal terminal. close.
At this time, we keep the terminal still, slightly press the micro switch, and observe the universal indicator at this time, it becomes 1, which means that the switch is connected to the line, indicating that the micro switch is normal.
In the same way, we test the other two wiring terminals of the micro switch, as shown in the figure:
When no pressure is applied to the micro switch, the display is 1, indicating that the two terminals are normally open.

Sino-Inst offers over 10 Liquid level float switches – Single and Multipoints for level measurement. About 50% of these are float liquid level meters, 40% is the level switches.

A wide variety of Liquid level float switches – Single and Multipoints options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of Liquid level float switches – Single and Multipoint instrumentation, located in China.