What is the primary function of a pressure switch?

The primary function of a pressure switch is to operate based on pressure changes. This device is designed to monitor the pressure within a system and activate or deactivate a circuit based on predetermined pressure thresholds. When the pressure reaches a certain point, the pressure switch can trigger an action, such as turning on a pump or opening a valve. This functionality is vital in numerous applications, such as maintaining system safety and ensuring operational efficiency by preventing damage from excessively high or low pressure.

In contrast, the other options focus on different parameters: regulating flow rates pertains to flow devices, indicating temperature changes is related to temperature sensors, and measuring hydraulic resistance would involve different measurement tools rather than a pressure switch. Each of these functions is critical in various contexts, but they do not encompass the primary role of a pressure switch, which is strictly linked to pressure variations.