937T Isolator Barriers

Our 937T Isolator Barriers include galvanic optical or transformer isolation, these modules provide an interface within the intrinsic safety circuit that is electrically separated from the control system. A key advantage of isolated barriers is that they do not require a ground between the module and the intrinsically safe device. Available in 12.5 mm (0.5 in) and 20mm (0.8 in) widths.

Bulletin 937T Isolator Barriers
  • Overview
  • Product Selection
  • Specifications
  • Documentation
  • Resources
  • Applications


  • Uses integrated diagnostics for simple maintenance and quick change of modules during ongoing operation
  • Uses DIP switches or Field Device Tool software for easy configuration
  • Provides easy and reliable planning and documentation with comprehensive standards compliance up to SIL 3
  • Offers horizontal or vertical mounting with no reduction in operational ratings
  • Includes line fault detection for field circuits
  • Provides power rail for reduced wiring, collective error messaging, and efficient troubleshooting and installation

Additional Information

Learn the basics of intrinsic safety circuits and how our Bulletin 937 Intrinsic Safety Modules can provide a cost-effective solution for hazardous location challenges.

To view commonly ordered and quickly available products, use the Product Configuration Assistant for our complete product offerings.


You can see a list of certifications for the Bulletin 937T Isolator Barriers by product number and link to the pdf of the certification document.

Product Certifications

Certifications apply when product is marked. See our Product Certification site for Declarations of Conformity, certificates and other certification details.

Configuration & Selection Tools

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Other Resources

  • Procurement Specifications — Visit our online resource to find the procurement specifications for this product.
  • Knowledgebase — Visit our online resource for technical information, support chat and forums, software updates, and product safety advisories/notices.


Zener Barrier Intrinsic Safety Modules are used in any application with Class 1, Division 1 (Zones 0 and 1) hazardous locations such as:

  • Chemical
  • Petrochemical
  • Oil and Gas

Essential Components Case Studies — View our case studies site to discover how customers have applied Allen-Bradley components in their applications.