In a hydraulic system, which device would primarily be used for safety reasons to prevent overextension of an actuator?

The primary role of a contact limit switch in a hydraulic system is to provide a safety mechanism for preventing overextension of an actuator. When the actuator reaches its predetermined limit, the contact limit switch is activated, which can interrupt the operation of the hydraulic system or signal other safety measures to be implemented. This function is crucial for protecting the actuator and the surrounding equipment from damage that might occur due to excessive travel beyond its designed limits.

In contrast, while a pressure switch is essential for monitoring system pressure and can provide safety features, it does not directly address the mechanical travel limitation of an actuator. A tachometer measures the speed of an actuator, providing important feedback for performance monitoring, but it does not serve as a preventive measure for overextension. Similarly, a linear transducer measures the position or displacement of an actuator, which can inform control systems about its current state, but it does not actively prevent overextension. Thus, the contact limit switch is specifically designed to ensure the safe operation of actuators by disabling them when they reach their maximum predetermined position, making it the most suitable choice for this safety function.