How many feet away is the sensing unit from the indicating and control panel?

• A. 100 feet
• B. 500 feet
• C. 1000 feet
• D. 50 feet

Answer: (B)

The distance between the sensing unit and the indicating/control panel is governed by how the detector communicates with the panel and how quickly the alarm needs to react. In many fixed gas detection setups, the sensing units are spread throughout the area to monitor for hazards, while the control panel stays in a central, monitored location. Keeping them about five hundred feet apart strikes a practical balance: it covers larger spaces without pushing the signaling lines into ranges where voltage drop, signal loss, or interference could slow or dull the alert.

With a run of roughly 500 feet, the wiring or network can be sized to maintain reliable power and a clear signal for timely alarms. Going much shorter, like around fifty or a hundred feet, would limit how widely you can place sensors in a larger facility. Going much longer, such as a thousand feet, increases the chance of signal degradation and typically requires repeaters or a different wiring strategy, adding cost and potential failure points. So, about five hundred feet is the distance that aligns with typical system design and ensures prompt, reliable indication at the panel.