Which tool is generally employed to measure the pressure of gases in a system?

The primary tool used to measure the pressure of gases in a system is the pressure gauge. Pressure gauges are specifically designed for this purpose; they provide a visual measurement of pressure in various units, such as pounds per square inch (psi) or bar. This allows for easy monitoring of gas pressure in a variety of applications, from industrial processes to HVAC systems.

In contrast, while a manometer can also measure the pressure of gases, it is typically used for more specific applications where precise differential pressure measurements are needed, such as in laboratory settings.

A thermometer measures temperature, which is unrelated to pressure. A multimeter is used for measuring electrical properties such as voltage, current, and resistance, and is not suitable for measuring gas pressure. Therefore, the pressure gauge stands out as the most appropriate and widely used tool for accurately measuring gas pressure in systems.