Double-hull atmosphere testing
What is being checked
The inspector is checking whether arrangements for testing double-hull and double-bottom spaces is suitable for the gases and spaces concerned, within calibration and test limits, understood by users and linked to an effective response.
Ready onboard
0/6 completePractice questions
Answer aloud, then open the preparation point.
1Why is this arrangements for testing double-hull and double-bottom spaces suitable?
Match the expected gases, measuring ranges and portable or fixed flammable-gas measurement and representative remote sampling arrangements to the space and operation.
2What is the difference between a bump test and calibration?
A bump test proves sensor and alarm response to gas. Calibration adjusts accuracy against a known concentration.
3How long must a remote sample be drawn?
Use the maker's pump and hose response time plus instrument stabilisation, accounting for hose length and gas characteristics.
4What happens after an alarm or sensor fault?
Follow cargo-operation control, investigation, increased monitoring, entry prohibition and emergency response; never treat a fault, inhibited channel or over-range reading as a safe atmosphere.
5Show the last complete test.
Trace tests of all designated sample points, hoses, pumps and portable instruments to the identified instrument or channel and its corrective action.
Where an observation may arise
The instrument or portable or fixed flammable-gas measurement and representative remote sampling arrangements did not suit the gas, range or atmosphere.
Users relied on a valid calibration sticker without a pre-use functional response test.
Calibration gas, certificate, sensor or battery status was expired or not traceable.
Hose response time, different levels, inaccessible areas or sample conditioning were not considered.
Personnel could not explain cargo-operation control, investigation, increased monitoring, entry prohibition and emergency response.
Inspection identified unreachable sample location, liquid-blocked hose, no purge time, defective pump or untested space.
Master's practical note
Challenge the whole measurement chain: atmosphere, sample point, hose, pump, sensor, display, alarm and user decision. A current calibration label proves only one part.
Equipment boundary and references
Equipment boundary: Use maker instructions for calibration gas, cross-sensitivity, poisoning, oxygen requirements and sampling limitations. Never use a catalytic sensor in an inert atmosphere unless approved for that purpose.
References
- OCIMF SIRE 2.0 Question Library Part 1, Version 1.0, Question 5.6.2
- SOLAS Chapter II-2 regulation 4.5.7.1
- OCIMF ISGOTT
Last reviewed: 2026-09-13