Red is what on the gauge?

• A. High
• B. Normal
• C. Critical
• D. Low

Answer: (D)

Red on this gauge marks the low end of the reading. Gauges use color bands to show status at a glance: green or white for safe/normal, yellow for caution, and red for an abnormal or critical condition. On this instrument, the red segment sits at the bottom, so a needle in red means the measurement is below the minimum safe level. Action is needed to bring the reading back into the safe range (such as refilling or reducing demand, depending on what is being measured).