Safety leak sensor for water and caustic chemicals

The SQ-4 Series is one of the first leak sensors in the industry to earn safety certification, demonstrating that it delivers safety performance of the highest caliber. Featuring a two-stage detection system for improved productivity, the SQ-4 simplifies preventative maintenance and maintenance planning.

  • Category 4 Rated - when used in combination, the SQ4-A sensor and SQ4-C11 controller meet Category 4/PLE/SIL3 requirements under ISO 13849-1:2008
  • Two-Stage Detection - dual sensing outputs provide both a warning and safety-critical output for differentiation of leak severity
  • Multiple Sensor Inputs - Up to four sensors can be connected to each controller
  • Independent Operation - Sensor heads can be used independently of the controller, meeting a Category 1 rating
  • Safety Input Function - Allows daisy chaining of multiple controllers along with safety peripherals such as e-stop and door switches


Increased productivity

The SQ-4 Series improves productivity with two-stage detection to report the occurrence of incipient and abnormal leak detection. 

Two-stage detection

The SQ-4 features two detection units for a two-stage detection, addressing incipient liquid leaks by generating a warning as well as abnormal liquid leaks by initiating an emergency stop. 


Human error detection

When the sensor itself becomes dislodge, has been improperly installed, or suffers from a broken connection, it will generate the same output as if a leak had occurred, ultimately detecting human error. 


Safety certification

The SQ-4 Series delivers safety to the highest standards and is designed to meet safety requirements imposed by international standards.  


Advanced level of safety control

Two independent CPUs simultaneously check the unit's operating state while redundant signal processing and output circuits ensure safety. 


Reduced costs

Reduce wiring and lower costs by connecting multiple units and controllers together into a single line.