Endress+Hauser CLS21-C1N3A Advanced Capacitance Level Switch for Reliable Point Level Detection

The Endress+Hauser CLS21-C1N3A is a state-of-the-art, rod-type capacitance level switch designed for precise and reliable point level detection in liquids, pastes, and granular solids. Engineered for demanding industrial applications, this versatile instrument serves as a high-performing, cost-effective solution for overfill protection, dry-run prevention, and pump control across a wide range of industries. From chemical and water treatment to food & beverage and plastics processing, the CLS21-C1N3A ensures process safety and efficiency through robust construction and intelligent signal processing.

Key Technical Parameters

• Measuring Principle: Capacitance with Active Guard for superior immunity to build-up.

• Process Connection: 1" NPT thread (C1), enabling easy installation.

• Process Temperature Range: -40 to +200 °C (-40 to +392 °F), suitable for extreme conditions.

• Process Pressure Range: Up to 25 bar (362 psi), robust for pressurized vessels.

• Electronics Housing: Polyamide, IP66/IP67 rated (N3), ensuring protection against dust and water ingress.

• Electrical Connection: M12 x 1 connector (A), for quick and secure cabling.

• Output Signal: SPDT relay (changeover contact), allowing flexible integration into control systems.

• Approvals: CE, EAC, and SIL 2 compliance according to IEC 61508, meeting high safety standards.

Core Advantages & Benefits

1. Unmatched Reliability with Active Guard: The patented Active Guard (Driven Shield) technology focuses the measuring field at the rod tip, effectively negating the effects of conductive coating or build-up on the probe or vessel wall. This guarantees stable switching points, minimizes false alarms, and drastically reduces maintenance needs.

2. Robust Design for Harsh Environments: With its wide temperature and pressure ranges, high IP rating, and corrosion-resistant materials (PTFE/PFA insulated probe), the CLS21-C1N3A performs reliably in aggressive media and challenging outdoor or washdown environments.

3. Simple Commissioning and Operation: Intuitive one-button calibration via Teach-In allows for fast, on-site setup without external tools. The clear LED status indicator provides immediate visual feedback on the switching state and device health.

4. Enhanced Process Safety: By providing accurate and dependable level detection, it prevents overfilling, spillage, and dry-running of pumps. Its SIL 2 capability makes it an ideal choice for safety instrumented systems, protecting personnel, assets, and the environment.

5. Versatile Application Fit: The standard rod probe is suitable for most liquids and solids. Optional process connections and probe lengths (up to 2m) allow customization for specific tank geometries and media types, offering excellent application flexibility.

Why Choose the CLS21-C1N3A?

The Endress+Hauser CLS21-C1N3A capacitance level switch combines proven technology with innovative features to deliver a maintenance-friendly and highly dependable point level solution. It stands out for its exceptional resistance to product build-up, ensuring long-term accuracy where conventional switches fail. This translates into increased process uptime, reduced operating costs, and superior plant safety. For engineers seeking a robust, "fit-and-forget" level switch from a global leader in measurement instrumentation, the CLS21-C1N3A represents the optimal choice.

Keywords: Endress+Hauser CLS21, capacitance level switch, point level detection, Active Guard, SIL 2, NPT thread, high temperature, high pressure, reliable level switch, overfill protection, dry-run protection, industrial level sensor.