In corrosive atmospheres, the detection devices for foam concentrate injection must be what?

• A. Made of materials not subject to corrosion or protected to resist corrosion
• B. Made of standard steel only
• C. Placed above ground without protection
• D. Not used in corrosive atmospheres

Answer: (A)

In corrosive atmospheres, detectors for foam concentrate injection must be built from materials that are not subject to corrosion or protected to resist corrosion. This ensures the devices remain reliable and accurate over time, since corrosion can degrade sensors, seals, wiring, and housings, leading to failed detection or false readings when foam needs to be injected.

Using corrosion-resistant materials—like stainless steel or specific corrosion-resistant alloys, or protective coatings and enclosures—helps maintain sensor integrity, calibration, and electrical connections in harsh environments. Simply using standard steel would allow corrosion to progress, compromising performance. Merely placing the devices above ground or avoiding use in corrosive atmospheres would not address the underlying need for reliable operation in such conditions, and is not acceptable practice.