Here are some frequently asked questions (FAQs) about ATEX level sensors, which are sensors designed for use in potentially explosive atmospheres:
What is an ATEX level sensor?
An ATEX level sensor is a level measuring device certified for use in hazardous environments where there may be explosive gases, vapors, or dust. These sensors comply with ATEX Directive 2014/34/EU, which governs equipment intended for explosive atmospheres in the European Union.
What does ATEX stand for?
ATEX stands for “Atmosphères Explosibles”, a French term that refers to explosive atmospheres. It commonly refers to two EU directives for controlling explosive atmospheres:
- ATEX 2014/34/EU (for equipment and protective systems)
- ATEX 1999/92/EC (for workplace safety)
Why do I need an ATEX-certified level sensor?
If your application involves flammable gases, liquids, vapors, or combustible dust, ATEX-certified sensors are required to prevent ignition sources that could cause explosions. Typical industries include:
- Oil & gas
- Chemical and petrochemical plants
- Mining
- Food and beverage (especially grain silos)
- Waste treatment
What level measurement technologies are available with ATEX certification?
Common ATEX-certified level measurement types include:
- Ultrasonic
- Radar (non-contact and guided wave)
- Capacitive
- Hydrostatic (pressure)
- Vibrating fork/tuning fork
- Float-based magnetic sensors
What do ATEX zone classifications mean?
Zones classify how often an explosive atmosphere is present:
- Gas atmospheres (Zone 0, 1, 2):
- Zone 0: Continuous presence
- Zone 1: Likely during normal operation
- Zone 2: Unlikely or short duration
- Dust atmospheres (Zone 20, 21, 22):
- Zone 20: Continuous presence
- Zone 21: Likely during normal operation
- Zone 22: Unlikely or short duration
The sensor must be rated for the zone in which it is installed.
How do I identify if a level sensor is ATEX certified?
Look for the ATEX marking on the product label or datasheet, which includes:
- The Ex symbol
- The equipment group (e.g., II for non-mining)
- The category (e.g., 1, 2, or 3)
- The gas/dust group and temperature class
Example: Ex II 1G Ex ia IIC T4 Ga
What is the difference between “intrinsically safe” and “explosion-proof”?
- Intrinsically Safe (Ex i): Limits electrical and thermal energy to prevent ignition in hazardous areas. Ideal for low-power systems.
- Explosion-Proof (Ex d): Encases potential ignition sources in a flameproof enclosure that can contain an explosion.
Both can be ATEX-compliant, but are suited for different installation conditions.
Can I install an ATEX sensor in a non-hazardous area?
Yes. ATEX sensors can be installed in non-hazardous zones, but this may increase cost unnecessarily if explosion protection is not needed.
Do ATEX sensors need special installation practices?
Yes. Installers must:
- Follow ATEX-certified wiring practices
- Use barriers or isolators for intrinsically safe circuits
- Use approved cable glands and enclosures
- Comply with zone classification and national safety regulations
What documentation should accompany an ATEX level sensor?
- ATEX certificate of conformity
- Declaration of conformity (DoC)
- Instruction manual with safety installation guidelines
- Marking plate with ATEX identification
If you need help choosing a specific ATEX level sensor for your application, feel free to share the details – tank size, medium type, zone classification, etc. We are here to help.