QUESTION 5.6.3

IGC Code fixed gas detection

LPG, LNGBridge, Cargo Control Room

What is being checked

The inspector is checking whether the fixed gas-detection system required by the IGC Code 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 complete

SUITABILITYInstrument type, measuring range and cargo-specific flammable and toxic sensors, sample lines, fans, alarm panels and locations required by the cargo containment arrangement suit the expected atmosphere and task.CALIBRATIONCalibration, sensor life, batteries, filters, sampling hoses and certificates are within maker and company limits.PRE-USE TESTA fresh-air zero and functional bump test are completed with the correct gas before use; calibration is performed when required.SAMPLINGSampling points, hose length, pump response time, different levels and remote or inaccessible portions are included.ALARM RESPONSEOfficers can explain set points, fault indications and cargo control, personnel evacuation, ventilation or ESD actions specified for the alarm location.RECORDRecords prove channel calibration, sample-flow alarms, fan changeover, alarm transmission and shutdown interfaces.

Practice questions

Answer aloud, then open the preparation point.

1Why is this the fixed gas-detection system required by the IGC Code suitable?

Match the expected gases, measuring ranges and cargo-specific flammable and toxic sensors, sample lines, fans, alarm panels and locations required by the cargo containment arrangement 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 control, personnel evacuation, ventilation or ESD actions specified for the alarm location; never treat a fault, inhibited channel or over-range reading as a safe atmosphere.

5Show the last complete test.

Trace channel calibration, sample-flow alarms, fan changeover, alarm transmission and shutdown interfaces to the identified instrument or channel and its corrective action.

Where an observation may arise

WRONG SENSOR

The instrument or cargo-specific flammable and toxic sensors, sample lines, fans, alarm panels and locations required by the cargo containment arrangement did not suit the gas, range or atmosphere.

NO BUMP TEST

Users relied on a valid calibration sticker without a pre-use functional response test.

CALIBRATION GAP

Calibration gas, certificate, sensor or battery status was expired or not traceable.

SAMPLING ERROR

Hose response time, different levels, inaccessible areas or sample conditioning were not considered.

ALARM MISUNDERSTOOD

Personnel could not explain cargo control, personnel evacuation, ventilation or ESD actions specified for the alarm location.

SYSTEM IMPAIRED

Inspection identified blocked sample line, failed fan, wrong gas calibration, inhibited channel or alarm not reaching the required station.

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 5.6.3
IMO IGC Code Chapter 13

Last reviewed: 2026-09-13