Mechanical gauges are instruments used to measure physical quantities such as pressure, temperature, or fluid levels. They operate based on mechanical principles, often using a dial and needle to display readings. Common types include pressure gauges, thermometers, and manometers, which rely on the movement of a mechanical component in response to changes in the measured variable. These gauges are typically simple to use and do not require electricity, making them reliable in various environments. They are widely used in industries like automotive, manufacturing, and HVAC systems, where accurate measurements are essential for safety and efficiency.