Products › Level instruments
Continuous level measurement, sorted by method. Pick by the tank and the medium: non-contact where you cannot or should not touch the liquid, a submerged probe where the surface is hard to see, and a differential-pressure transmitter for closed and pressurized vessels. Each links to the full product page.
Non-contact level
Ultrasonic Level TransmitterNon-contact FMCW radar to 150 m, 1 mm accuracy.
Ultrasonic Level TransmitterNon-contact echo, 4–20 mA or RS-485; open tanks, sumps and channels. Not for pressurized vessels.
Radar Level TransmitterNon-contact 120 GHz FMCW, 2 mm accuracy to 150 m, density-independent.
Submerged and hydrostatic level
Hydrostatic Level TransmitterSI-151: submerged probe, 0 to 200 m H₂O, ±0.2% FS, IP68; head pressure P=ρgh.
Stainless Steel Submersible Level TransmitterGas-conducted submersible level transmitter for hot, corrosive, and sewage liquids; the sensor stays out of the medium.
SI-302 Anti-corrosive Submersible Level TransmitterPTFE submersible level transmitter for acid, alkali, sludge, and slurry.
Submersible Pressure TransducerSI-PCM261: 0–0.5 to 0–300 m, ±0.5% FS, IP68 on vented cable; wells and deep sumps.
SI-PCM260 Deep Well Water Level SensorDeep-well water level probe on a stainless cable for boreholes to about 1000 m.
Differential pressure level
DP Level TransmitterSMT3151LT: spans 4 kPa to 2.1 MPa, 0.1% FS, 4–20 mA + HART; flange or capillary for closed tanks.
Diaphragm Seal TransmitterFilled seal + capillary, ±0.1% span, 4–20 mA + HART; sticky or aggressive media for level service.
Contact and precision level
Contact methods place a probe in the tank for the highest accuracy and the best immunity to foam, coating, and a changing dielectric. Magnetostrictive leads here, reading to a fraction of a millimetre.
Float Level SwitchCable float switch for pump on/off and level alarms.
SI-100 MagnetostrictiveRigid-probe transmitter reading to 0.1 mm, immune to coating and foam.
RF Admittance Level SensorIgnores coating and buildup; sticky, conductive, and hot media to 800 C.
Guided Wave RadarContact TDR probe for low-dielectric, agitated, and powder media.
Choosing a level method
| Method | Best when | Avoid when |
|---|---|---|
| Ultrasonic | Open, calm surface; no contact wanted | Foam, vapor, pressurized tanks |
| Hydrostatic / submersible | Open tanks, wells, sumps; simple and low cost | Density that shifts; very high accuracy |
| Differential pressure | Closed or pressurized vessels | Simple open tank (overkill) |
Tell us the tank, the medium and the range, and our application engineers will route you to the right method and a configured model. Reach our application engineers.
New to the method? See how a hydrostatic pressure transmitter reads level from head pressure, and how submersible and flush-mount types compare.
FAQ
What is a level sensor?
A level sensor is an instrument that measures how much liquid or solid sits in a tank, silo, or open channel and turns it into a signal a control system can read. Depending on the method it senses the surface from above, reads the head of liquid from below, or detects a change along a probe. The right one depends on the material, the temperature and pressure, and how clean or aggressive the medium is.
What are the different types of level sensors?
Level sensors split into non-contact and contact methods. Non-contact types like radar and ultrasonic measure from the top of the vessel without touching the medium. Contact types include hydrostatic and submersible probes that read the head of liquid, and differential pressure transmitters for sealed or pressurised tanks. You choose by the medium, the vessel, and whether contact is acceptable.
What is the difference between a level sensor and a level switch?
A level sensor measures level continuously across the full range and reports it as a 4-20 mA or digital signal. A level switch only signals when the liquid reaches one point, opening or closing a contact for a high or low alarm. Use a continuous sensor when you need to trend or control level, and a switch when you only need a fill or empty trip; many tanks use both together.