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Float level devices use a buoyant magnetic float and sealed reed switches to detect liquid level. They are simple, rugged and need no power in the wetted path, which makes them a first choice for level switching and basic level reading on water, oil, fuel and chemical tanks. Choose a continuous sensor, a multipoint switch or a cable float switch by what the tank has to do.
Float level sensors and switches
Float Level SensorSingle, multipoint or continuous 4-20 mA magnetic float level sensor; insert to 6 m, PN to 320.
Multipoint Float SwitchSeveral reed set points on one stem; 304/316L, PP or PTFE/PVC builds for corrosive media.
Float Level SwitchCable-suspended float switch (SI-U05) for pump start/stop in open tanks and sumps.
Choosing a float level device
| What you need | Choose |
|---|---|
| A live level reading (4-20 mA) or single to multipoint points on an insertion | Float Level Sensor |
| Several on/off points in one tank, with a material to match the medium | Multipoint Float Switch |
| Pump start/stop in an open tank, sump or reservoir | Float Level Switch (cable) |
FAQ
What is a float level sensor?
A float level sensor detects liquid level with a buoyant magnetic float and reed switches. The float rides on the surface along a stem; each reed closes at its height to give a switch point, or a reed-resistor chain gives a continuous 4-20 mA reading.
How does a float switch work?
A magnet in the float closes a sealed reed switch when the float reaches it. One float gives a single point; several floats give several points. The medium density must be above 0.5 g/cm³ for the float to stay buoyant.
How accurate are float sensors?
Switch points repeat to about plus or minus 10 mm, set by the reed spacing. Float devices are valued for rugged, repeatable switching; for a fine continuous level use the 4-20 mA sensor build or a magnetostrictive or radar device.
Request a quote
Tell us the tank height, the medium and its density and temperature, and whether you need a reading, switch points or pump control, and we configure one unit for the application, not a shelf part.