Level instruments & probes

Precise level measurement with our leakage probes and overfill protections, according to the German Water Resources Act (WHG) with EX approval and SIL

Full product range

Note for our customers: This is only an extract of our product range on the subject of level instruments. Our full product list with further information can be found here:  E.L.B. Füllstandsgeräte (a company of ZILA GmbH).
If you have any questions, please do not hesitate to contact us, using the contact information provided. We will be pleased to fulfill your request. 

Overfill protection devices / Ex / WHG / SIL

Füllstandsmesser Füllstands- und Pegelsonde

Our level sensors are approved as limit switches for overfill protection systems by the German Institute for Construction Engineering (DIBt) and are used for storing water-contaminating liquids. As soon as the level rises, the float switch activates the reed contacts installed in the guide tube through a magnetic system. Any change in resistance in the sensor circuit, triggered by switching, will then be evaluated by the system and the output relay will be activated. The wetted parts of the level sensors are entirely made of PE, PP, PCV, PVDF.

This makes the level sensors ideal for use in tanks storing extremely aggressive media.

More product information:

Overfill protction devices / Ex / WHG / SIL

Overview overfill protection devices


Leak detectors / Ex / WHG / SIL

Füllstandsmesser leckagesonde

Our leak detectors are approved by the German Institute for Construction Engineering (DIBt) for detecting leaking, water-contaminating liquids in accordance with the regulation "WasBauPVO". This regulation determines the qualification of construction products and types under German Water Law.

Amongst other locations of use, they can be applied in the space between a tank and its collection tray.

More product information:

Leak detectors / Ex / WHG / SIL

Alarm indicators / WHG / SIL with approval by the German General Construction Supervision Authority


Alarm indicators are stand-alone devices for alarm indication and signalling an alert of an overfill protection device or a leakage probe. They detect limit value signals of the connected level sensors / leakage probes and trigger an acoustic signal (acknowledgeable) and an optical signal (non-acknowledgeable).

The main field of application and use, when used with an overfill level sensor and a leakage probe, is on-site tank monitoring.

More product information:

Alarm indicators / WHG / SIL

Contacts / Ex / SIL &

floats and weights

Kontakte /Ex/SIL, Schwimmer, Gewichte

The floats and weights with magnetic elements are used along with our level instruments MTA, ÜTA and W-35...

The bistable contacts BK-380 and BK-390 are magnetically operated changeover switches, changing their electrical switching state, when a magnetic system passes by, depending on the direction of movement of the magnet. They can be (retro-)fitted onto level indicators, e.g. our water level indicator W-35..., the tank level indicator MTA-50 or the over-tank indicator ÜTA-32... etc. in order to control the liquid level.

Our floats and weights with magnetic insert are also used along with our MTA, ÜTA and W-35... level devices.

More product information:

Contacts / Ex / SIL & floats and weights

Bistable contacts BK-380 and BK-390

Floats and weights with magnetic core

Electrodes &

Ex electrodes / zone 0 / WHG / SIL / Ex / SIL

Elektroden & Ex-Elektroden Zone 0/WHG/SIL/Ex/SIL

When using a level electrode together with a ground electrode, it is possible to detect when the level exceeds or falls below a limit. The electrodes can be mounted in all positions. This allows the electrode rod to be screwed in manually.

Our conductive electrodes can be used in min-max controls, limit value signalling and as dry and overflow protection in combination with our electrode relays for example.

More product information:

Electrodes Ex / SIL

Electrodes Ex zone 0 / WHG / SIL

Overview electrodes

Float switches / Ex / SIL / RoHS

Schwimmschalter /Ex/SIL/RoHS

Float switches are used for simple limit value detection. Because of the liquid's higher density, the float swims on its surface and triggers a switching operation when there is a deviation from its horizontal position. This is a simple way to control the level of fluids.

When using 2 float switches, one working as a maximum contactor and the other as a minimum contactor, you will achieve automatic level control. In addition, the float switches can be used as overflow and dry run protection.

More product information:

Float switches / EX / SIL

Float switches / Ex / SIL / RoHS

Overview float switches

Overview float switches / Ex / SIL / RoHS

Magnetic immersible probes / zone 0 / Ex / WHG / SIL

Magnettauchsonden /SIL & Ex-Magnettauchs. Zone 0 /WHG/SIL

Our magnetic immersible probes can detect level limits for liquid media in containers. Depending on the requirements, the materials used are PVC, PE, PPH, PTFE, brass or stainless steel (1.4571).

Our explosion-proof magnetic immersible probes can also be used to detect limit values in containers for liquid media, where an explosive atmosphere of category 1 (zone 0) can be found in the space above the liquid and category 2 (zone 1) outside the container in the area of the connection socket.

Due to the high-quality materials used, all of our magnetic immersible probes are also suitable for use with highly aggressive media.

More product information:

Magnetic immersible probes / Ex / SIL

Magnetic immersible probes zone 0 / WHG / SIL

Overview magnetic immersible probes

Type codes and connections

Pneumatic level switches

Pneumatische Niveauschalter

Our pneumatic level switches are highly reliable and easy-to-use sensors for liquid detection, especially suitable for overflow protection. It does not matter whether the fluids are aggressive, sticky or highly contaminated - our level switches work reliably in any fluid, even the most contaminated ones.

Moreover, the switches can be used to signal minimum levels. However, use is only permitted in open and unpressurised containers, tanks, etc.

More product information:

Pneumatic level switches

Pneumatic level switches NP-250 ... NP-253

Pneumatic level switches NP-255 and NP-256

Hydrostatic limit switches

Kapazitive Sonden

Our hydrostatic limit switches have been designed for use in liquids, including aggressive liquids in unpressurised containers and tanks. The hydrostatic pressure of the medium used affects the membrane of the measuring cell inside the sensor and thus causes a change in an electrical parameter. This change is then converted into an output signal via an integrated electronic evaluation system.

More product information:

Hydrostatic limit switches

Overview hydrostatic limit switches

Vibration limit switch


The vibration limit switch is a level limit switch for any kind of fluid and is applied in tanks, containers and pipelines. For example, it can be installed in cleaning and filter systems as well as in coolant and lubricant tanks as an overfill or a pump protection. Its function is also ensured in areas where other measuring principles do not work, due to conductivity, deposits, turbulences, currents or air bubbles.

More product information:

Vibration limit switch

Vibration limit switches NSP-1-E and NSP-2-E

One-channel and two-channel amps & transducer relays / Ex / WHG / SIL

Schaltverstärker/Relais /Ex/WHG/SIL

The electrode relays are used for conductive level detection. Possible applications include all areas in which liquid, conductive media must be detected, controlled or regulated in any way. This can include both limit level detection (overflow / dry run) and min-max controls.

More product information:

Ams & transducer relays

Overview amps

Continuous immersible probe / SIL / Ex made of brass and stainless steel

Kontinuierliche Tauchsonden /SIL/Ex

The main application of our continuous magnetic immersible probes TK30... is continous liquid level detection in containers. Depending on the requirements, they are made of PVC, PE, PPH, PTFE, brass or stainless steel (1.4571).

This makes our magnetic immersible probes suitable even for use in highly aggressive media.

More product information:

Continuous immersible probes / SIL

Continuous immersible probes / Ex / SIL

Overview continuous immersible probes / SIL

Type codes and connections / SIL

Overview continuous immersible probes / Ex / SIL

Type codes and connections / Ex / SIL

Hydrostatic screw-in probe / SIL

Hydrostatisch, kontinuierlich /SIL

In our hydrostatic screw-in probes, the hydrostatic pressure of the medium affects the diaphragm of the measuring cell in the sensor and causes a change of an electrical parameter. This change can then be converted into a corresponding output signal via an integrated electronic evaluation system.

It is used for level measurement in water and in clean to slightly contaminated liquids, as well as in acids, alkalis or aggressive media. Its main area of application includes unpressurised containers and tanks.

More product information:

Hydrostatic screw-in probe

Overview hydrostatic level measurement

Evaluation & display units / SIL

Auswertegeräte und Anzeigen

Our evaluation units convert a resistance signal supplied by our continuous immersible probes into a current signal proportional to the liquid level. This standard current signal (0 / 4...20 mA) can be used for displaying, registering and controlling levels or other process variables in a three-wire circuit.

The indicators, in contrast, are used when process states, such as filling levels, need to be displayed visually. Due to the fact that the input variables and the display range can be parameterised, they can be applied universally and are also perfectly suitable for difficult areas, e.g. a bright environment.

More product information:

Evaluation displays and units

Turbidity measurement

Trübungssensor zur Trübungsmessung

Our turbidimeter TRM-100 is a compact device for measuring turbidity in liquids. Turbidity is measured by the scattered light method (angle 90 degrees) for the turbidity range < 1,000 FNU (Formazine Nephelometric Units) and by the transmitted light method (angle 0 degrees) for the turbidity ranges > 1,000 FAU (Formazine Attenuation Units).

More product information:


Turbidimeter TRM-100

Warning system / oil & grease separator / Ex / SIL

Warnanlage Öl/Fett Abscheider /Ex/SIL

The warning system OAA-400-A1/A2  is used to monitor oil, petrol, grease or light liquid separator systems in hazardous areas.

Monitoring options: Accumulation: Monitoring of the maximum liquid level

Leakage detection: When the liquid level drops, e.g. in the event of a leak

Boundary layer: Monitoring of a defined oil layer thickness
Sludge level: Detection of the sludge level / sand

The condition of connected sensors as well as their signal lines are monitored for line break and line short circuit.

More product information:

Warning system for light liquid seperator OAA-400-A1/A2

Warning system for light liquid separator OAA-400-A1/A2

 Prices and availability

For an individual offer for our level instruments and probes, please contact us by phone at
+49-6251-8462-0 , by email under This email address is being protected from spambots. You need JavaScript enabled to view it.  or by using our contact form.
Our experienced sales team is looking forward to your enquiry!

Blog posts about level devices

Level measurement in open containers with our hydrostatic probes

Level measurement in open containers with our hydrostatic probes

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Ready-to-use solutions for monitoring environmentally hazardous substances

Ready-to-use solutions for monitoring environmentally hazardous substances

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Capacitive limit level monitoring according to WHG in the Ex area

Capacitive limit level monitoring according to WHG in the Ex area

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ZILA GmbH and E.L.B. Füllstandsgeräte GmbH side by side

ZILA GmbH and E.L.B. Füllstandsgeräte GmbH side by side

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Quotation, price information and ordering

Many of our products can be adapted to their fields of application and use individually. Besides the individual factory-set parameters, such as the different measuring ranges, the surrounding media and electrical connections and accessories are also important aspects for the offer.
Therefore, let us advise you professionally and without any obligation!
Our experienced sales staff will be pleased to prepare a suitable offer for you quickly.

Your contact options

Business times:
Monday - Friday 8:00 - 17:00 (CET)


Phone: +49-6251-8462-0

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