Mechanical gauges are instruments used to measure physical quantities such as pressure, temperature, or fluid levels. They operate using mechanical components, like springs or diaphragms, which respond to changes in the measured variable. The readings are displayed on a dial or scale, providing a direct visual indication of the measurement. These gauges are commonly found in various applications, including automotive systems, industrial machinery, and HVAC systems. Examples include pressure gauges, thermometers, and manometers. Unlike electronic gauges, mechanical gauges do not require power sources, making them reliable in environments where electricity may not be available.