What is a key characteristic of a Normally Closed proximity sensor?

• A. It activates when triggered
• B. It remains active when untriggered
• C. It works only in high temperatures
• D. It requires a continuous power supply

Answer: (A)

A Normally Closed proximity sensor is designed to keep its output in an active state when no object is present, meaning it is “closed” in its default condition. When the sensor detects an object or is triggered, it switches to an inactive state, or "open." This design is particularly useful in safety applications where the default state should indicate that everything is normal until something interrupts that condition.

The essence of this characteristic is that the sensor is primarily active until the condition changes, which aligns with the expected operation of a Normally Closed sensor. Such sensors are typically employed in systems where maintaining a constant signal is critical until an event, like the presence of an object, occurs, which would change the output state.

Understanding this behavior is crucial for implementing sensors in various automation and control systems, ensuring proper functionality tailored to specific applications. The other options suggest scenarios that do not accurately reflect the operational nature of a Normally Closed sensor.