A vacuum gauge is a device used to measure the pressure in a vacuum system. It helps determine how much air or gas has been removed from a sealed environment, indicating the level of vacuum achieved. Vacuum gauges are essential in various applications, including laboratories, industrial processes, and HVAC systems. There are different types of vacuum gauges, such as mechanical gauges, electronic gauges, and capacitance manometers. Each type operates on different principles and is suited for specific pressure ranges. Accurate measurements from vacuum gauges are crucial for ensuring optimal performance and safety in systems that rely on vacuum conditions.