Which device opens the interlock circuit when airflow falls below the threshold?

Which device opens the interlock circuit when airflow falls below the threshold?

• A. Airflow switch or transducer
• B. Heat sensor
• C. Humidity sensor
• D. Pressure switch

Answer: (A)

The device being tested is an airflow switch or transducer. It’s specifically designed to monitor the actual flow of air in the system. When airflow is within the required range, the switch keeps the interlock circuit intact. If airflow falls below the set threshold, the switch opens the circuit, triggering the interlock to shut down or prevent the system from discharging until proper ventilation is restored. This ensures the extinguishing system only operates under safe, properly ventilated conditions. Heat sensors, humidity sensors, and pressure switches serve other roles. A heat sensor responds to high temperatures to detect fire risk, not to airflow levels. Humidity sensors measure moisture, which isn’t what the interlock uses to determine safe operation. A pressure switch monitors pressure differences, which can relate to airflow in some contexts but isn’t the standard device used to open an interlock based on airflow threshold.

The device being tested is an airflow switch or transducer. It’s specifically designed to monitor the actual flow of air in the system. When airflow is within the required range, the switch keeps the interlock circuit intact. If airflow falls below the set threshold, the switch opens the circuit, triggering the interlock to shut down or prevent the system from discharging until proper ventilation is restored. This ensures the extinguishing system only operates under safe, properly ventilated conditions.

Heat sensors, humidity sensors, and pressure switches serve other roles. A heat sensor responds to high temperatures to detect fire risk, not to airflow levels. Humidity sensors measure moisture, which isn’t what the interlock uses to determine safe operation. A pressure switch monitors pressure differences, which can relate to airflow in some contexts but isn’t the standard device used to open an interlock based on airflow threshold.