A pressure gauge is a device used to measure the pressure of gases or liquids in various systems. It provides important information about the pressure levels, helping to ensure safety and efficiency in applications like industrial machinery, HVAC systems, and automotive engines. Pressure gauges can be analog, using a dial and needle, or digital, displaying readings on a screen. These gauges work by sensing the force exerted by the fluid against a diaphragm or a Bourdon tube, which then translates this force into a readable measurement. Regular monitoring of pressure levels can prevent equipment failure and maintain optimal performance in systems where pressure is critical.