Compound gauge measures which characteristic?

• A. A pressure gauge that measures only positive pressure
• B. A pressure gauge capable of measuring positive and negative pressures
• C. A device for measuring temperature
• D. A gauge for measuring flow

Answer: (B)

A compound gauge is designed to read both positive pressure and negative pressure (vacuum). It combines two scales so you can see pressures above ambient (psig) and below ambient (vacuum, such as inches of mercury). This lets you monitor systems that can operate with either positive pressure or sub-atmospheric conditions. It’s not a temperature gauge or a flow gauge, which is why those options don’t fit.