What are the problems with installing intrinsically safe instruments without a safety barrier?

Intrinsic safety instruments are designed for use in explosive areas, by limiting the energy that can be generated within electrical equipment to prevent ignition of flammable gases in the surrounding area. When used in non-explosion-proof areas, not installing a safety barrier may not cause problems immediately, but if a malfunction occurs while the instrument is connected to other devices, it could generate enough energy to ignite the surrounding environment, thus posing a safety hazard. Using non-intrinsic cables to connect to the DCS without installing a safety barrier may violate relevant safety regulations and standards, especially in environments where flammable and explosive materials are present. Even in non-explosion-proof areas, if future environmental changes classify the area as an explosion-proof zone, installations that do not meet the standards will become a problem. As for the communication issues related to NAMUR signals and other signals, it mainly depends on the compatibility between devices and the interface standards to determine whether they can be used properly. In general, it is not illegal to use intrinsically safe instruments in non-explosion-proof areas, but to ensure long-term safety and compliance with regulations, it is recommended to install them using the correct methods, including safety measures such as safety barriers. .

I majored in process engineering. From my understanding, if a safety barrier is not installed, it does not constitute intrinsically safe operation; therefore, it is not an intrinsically safe instrument

There’s no problem; the gauge works properly, but it’s just like an ordinary gauge – it doesn’t have any explosion-proof features.

Intrinsic safety instruments do not constitute intrinsic safety without a safety barrier； Intrinsic safety instruments can be used as non-intrinsic safety instruments ； If the application site does not have explosion-proof requirements, a safety barrier is not necessary; in this case, the instrument does not possess intrinsically safe functionality. .

In intrinsically safe systems, there are two concepts: intrinsically safe instruments and intrinsically safe circuits. All components that make up this intrinsically safe circuit (including cables) must be intrinsically safe; the safety barrier serves to limit the electrical energy reaching the field, so that any sparks that may occur in case of a failure will not ignite the explosive gas mixture present there. Of course, the instruments in the intrinsically safe circuit must be intrinsically safe instruments. Inertial instruments are those that, in the event of a failure, will not ignite the explosive gas mixture present in the area; they are also known as safe-spark instruments. By using intrinsically safe instruments instead of safety barriers, the instruments can function properly, but they cannot form an intrinsically safe circuit; therefore, they do not possess explosion-proof capabilities. The question is: if there are no explosion-proof requirements, why choose intrinsically safe instruments?