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Wish I knew how an intrinsic safety barrier works!

There are several ways to make an application safe in hazardous areas, like sand filling, oil immersion, and – today’s topic – intrinsic safety barrier. If you don’t work in hazardous conditions, you may not see this method often. Safety is a huge topic in all industries, so many vendors certify their products and review safety during project discussions.

The intrinsic safety barrier, known as an IS barrier, protects a field device installed in a hazardous area. It limits the energy put out by the device just enough to reduce the risk of igniting flammable gases.

An intrinsically safe installation has three essential elements, the field device, the IS barrier, and the field wiring. The graphic should give you an idea of what I mean:

Intrinsic safety barrier
Courtesy of Sensorland.com

This setup uses zener diodes, fuses, and resistors. IS barriers work normally until fault conditions occur. Then the barrier will channel the faulty current away from the device. Here, when a fault occurs, the zener diode sends the current to the ground and the fuse opens.

This video can show you how the principle of intrinsic safety works:

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