Explosion-proof sensor works - Solutions - Huaqiang Electronic Network

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When working in flammable or explosive environments, it's essential to use explosion-proof sensors to prevent potential hazards. There are three primary methods for achieving explosion protection: controlling the presence of explosive gases, managing the explosion limits, and isolating the ignition sources.

The first method involves using a positive pressure explosion-proof system. In this approach, the sensor is enclosed in a sealed housing filled with an inert or clean gas at a slightly higher pressure than the surrounding atmosphere. This prevents any flammable gases from entering the enclosure and ensures safe operation. This technique is commonly referred to as "Ex d" or "positive pressure type" explosion-proofing.

The second method follows strict international standards such as Exd, where the sensor casing is designed to withstand internal explosions without allowing them to propagate to the external environment. The design, manufacturing, and assembly processes must adhere to rigorous specifications to ensure that even if an explosion occurs inside the enclosure, it won't ignite the surrounding hazardous gases.

The third method focuses on limiting the energy supplied to the field device. By using a safety barrier, the electrical power delivered to the sensor is restricted to levels that cannot cause a spark or heat sufficient to trigger an explosion. This method is often used in areas where continuous operation is required, as it allows for safer maintenance and wiring procedures.

Each of these methods has its own advantages and applications. While some may require more complex setups or regular maintenance, they all play a critical role in ensuring safety in high-risk environments. It's important to choose the right type of sensor based on the specific application and environmental conditions.

When purchasing sensors for potentially explosive environments, always consider both the intrinsic safety (IS) and explosion-proof (Ex) types. Be sure to ask your supplier for the relevant certification, such as the Ex certificate, to confirm that the equipment meets the necessary safety standards.