Definition
A sealed, pressurized test chamber used to check the operation and calibration of pressure-sensing instruments and components, such as altimeters, airspeed indicators, and pressure switches. The unit being tested is placed inside the chamber, and the internal pressure is varied in a controlled way to simulate different altitudes or operating conditions while the instrument's response is observed.
Plain English
A strong, sealed container that mechanics use to change the air pressure around an instrument so they can check whether it reads correctly at different simulated altitudes.
Context Anchor
Seen in aircraft maintenance shops during spark plug cleaning, inspection, or troubleshooting for a rough-running engine.
Derivation
Called a 'bomb' because of its thick, heavy, sealed construction, which resembles the shape of an old-style bomb casing capable of containing high pressure safely. The name describes the housing, not any explosive function.
Why Pilots Care
Confirms the ignition system will deliver reliable sparks in flight, reducing risk of engine misfire or failure.
Intuition Check
Do not read “bomb tester” as a tool for testing bombs or explosives. In this maintenance context, it means a pressure-chamber tester for spark plugs.
Example Sentence 1
The technician placed the altimeter in the bomb tester and slowly reduced the internal pressure to verify its readings at simulated altitudes up to 20,000 feet.
Example Sentence 2
Before reinstalling the harness, the technician ran each lead through the bomb tester to locate any insulation breakdown.