Float activated switches for opening or closing electrical contacts at a preset fluid level.
Float fluid level switches are threshold contact trip devices which typically consist of a buoyancy component which is typically a sealed hollow ball or cylinder which will float on a fluid, and either a shaft assembly for vertical mounting, or a hinge mechanism for horizontal mounting.
As the level increases and decreases a float will be pushed up or drop down. The float can be connected to a hinge that opens and closes or slides along a shaft.
The position of the float along the shaft or the opening and closing of the hinge can be detected by various means.
A vertical mount sliding float type level switch will have a permanent magnet incorporated into the float which slides up and down the shaft. A magnetic reed switch is positioned along the shaft to the required level set point. When the float pashes over the reed switch it will open or close the level switch circuit.
A horizontal mount hinged type float level switch will incorporate either a microswitch or a magnetic reed switch, which is activated by an actuator or lever connected to the float.
It is possible to fit more than one switch to shaft type float switch, and provide fluid level control for a number of separate processes which are activated at different levels.
Featured liquid level measurement products
SWL Marine Bronze Submersible Level Sensor - Analogue output sensor for immersing in seawater to determine depth or change in water level by measuring hydrostatic pressure.
4-20mA Output Hydrostatic Level Transmitters & Sensors - Explore industrial 4-20mA hydrostatic level transmitters for reliable liquid depth measurement. Ideal for tank gauging, borehole control & process monitoring applications.
Glossary of Liquid Level technical terms
- Capacitive Fluid Level Measurement
- cmH2O – Centimetres of Water Column at 4 deg C Pressure Unit
- Conductive Fluid Level Detection
- ftH2O – Feet of Water Column at 4 deg C Pressure Unit
- Hydrostatic Pressure
- mH2O – Metres of Water Gauge at 4 deg C Pressure Unit
- mmH2O – Millimetres of Water Column at 4 deg C Pressure Unit
- Specific Gravity
- Vibrating Tuning Fork Fluid Level Detection
Help from Liquid Level resources
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- Determining water tank volume using hydrostatic pressure
- Difference between vented and non-vented water level measurement
- Measuring the volume of liquid in a horizontal cylinder tank
- How do you measure the volume of a liquid using pressure
- Measuring liquid level in a tank using a dp sensor


