Certified to ATEX, IECEx, and UKCA standards, the LLIS sensor combines advanced optical sensing technology with rugged construction. Its real-time liquid level detection operates safely without introducing ignition risks—making it ideal for industries such as oil and gas, petrochemical, chemical processing, and environmental monitoring.
Why Intrinsic Safety is Critical
In explosive zones (0, 1, or 2), even minor electrical faults can have devastating consequences. The LLIS sensor is designed within strict intrinsic safety (IS) parameters, using low-voltage, low-current circuits in conjunction with certified IS barriers or isolators. It complies with ATEX Directive 2014/34/EU, IECEx, and accounts for both capacitance and inductance to ensure safe energy levels—reliable even during fault conditions.
High-Precision Optical Sensing
At the heart of the LLIS is a total internal reflection-based infrared sensor. This design instantly detects liquid presence via light refraction—delivering highly repeatable results with a switch point accuracy of ±1 mm. With no moving parts, the sensor offers maintenance-free operation and does not require frequent calibration, making it an excellent fit for:
- Leak detection systems
- Tank level monitoring
- Analyzer protection
Built to Perform in Extreme Conditions
From frozen outdoor tanks to high-temperature process vessels, the LLIS is built to last. It features:
- Durable 316 stainless steel housing
- Sensor tips in polysulfone, trogamid, or grilamid to match fluid compatibility
- Wide operating temperature range: –30°C to +80°C
- IP68/IP69-rated cable connectors (2, 5, or 10m NAMUR)
- Compatible SIL2 NAMUR isolated barrier (24VDC, 1-channel)
This robust setup ensures protection against dust, moisture, and even full submersion or frequent washdowns.
Effortless Integration & Global Compliance
With its NAMUR standard output and availability in both metric and imperial process connections, the LLIS is easy to integrate into existing hazardous area systems. It is fully certified for use in explosive environments:
- ATEX II 1 G Ex ia IIC T4 Ga – Zones 0, 1, and 2
- IECEx Ex ia IIC T4 Ga – International safety compliance
- UKCA Approved – Fully compliant with post-Brexit UK regulations
- Conforms to EN IEC 60079-0:2018 and IEC 60079-11:2023
Applications Across Critical Industries
The LLIS sensor plays a key role in protecting people, processes, and equipment in high-risk sectors, including:
- Diesel and fuel tank monitoring
- Leak detection in air-operated diaphragm pump systems
- High-level sewage screening in Zone 2 areas
- Live system testing involving explosive liquids like gasoline, diesel, or hydrogen
Its suitability for low-flashpoint, volatile liquids, where vapours can form explosive atmospheres, makes it indispensable for hydrogen energy and transition projects.
Reliable, Certified, and Built for Safety
The LLIS Liquid Level Sensor from SST Sensing sets a new benchmark in hazardous area instrumentation. With fast, precise detection, robust industrial design, and trusted global certifications, it empowers operators to confidently manage liquid levels in the most demanding conditions.
To learn more or request a quote, contact our engineers at sensors@processsensing.com
