What effect does a decrease in core resistance have in a continuous loop fire detection system?

In a continuous loop fire detection system, a decrease in core resistance indicates a change in the conductive properties of the sensing element, which is typically a thermistor or similar device that reacts to heat. As the temperature increases, the resistance of the sensing element decreases. When this drop in resistance occurs, it creates a condition that the fire detection system interprets as a potential fire or abnormal heat condition.

This change in resistance alters the electrical circuit in a way that sends a signal to activate the fire alarm. Hence, when the core resistance decreases significantly, the detection system recognizes this as an alarm condition and activates the alarm system to alert personnel of a potential fire hazard.

The other options suggest outcomes that do not align with the fundamental operation of continuous loop fire detection systems. For example, deactivating the alarm would imply that there is no longer a perceived threat, which is not the case with a decrease in core resistance indicative of a rise in temperature. Similarly, a delay in alarm activation would not occur because a drop in core resistance typically results in an immediate response from the system, compelling it to react promptly to potential danger. Therefore, the most accurate understanding is that a decrease in core resistance activates the alarm system.