Describe a basic approach to diagnosing an abnormal reading on a pressure gauge.

• A. Immediately replace the gauge and ignore other readings.
• B. Verify gauge accuracy, check upstream and downstream components, look for leaks or blockages, and recalibrate.
• C. Increase system pressure to see if reading changes.
• D. Shut down the system and restart without inspection.

Answer: (B)

When a pressure gauge shows an abnormal reading, start by confirming the instrument itself is accurate and then look for issues in the surrounding system. Check the gauge against a known-good instrument or perform a calibration check; if it’s drifted, recalibrate or replace the gauge as needed. Next, inspect both sides of the gauge—upstream components like the supply line, valves, and regulators, and downstream components such as filters and actuators—for leaks, blockages, or partial restrictions that could skew the reading. Leaks can drop pressure or cause fluctuations, while blockages or restrictions can create abnormal indications, so identifying these helps distinguish instrument fault from system fault. If the gauge is accurate and no faults are found in the line, recalibrate to ensure the reading reflects true pressure. Avoid changing system conditions or replacing the gauge without verification, and if possible, cross-check with another gauge to confirm the reading.