Gas Detectors Combination

State the gases and the range for each (for flammables, whether %LEL or %vol), whether a built-in sampling pump is needed to draw from deep tanks and the sampling-hose length, and the explosion-protection rating needed for the areas where it will be used. Say whether the unit is the instrument for testing before entry or a personal monitor; the two are not interchangeable.^[3]

Give the make and model already on board if the order is for sensors, filters, chargers or calibration gas, because these are model-specific. For calibration gas, state the gas mixture and concentration the manufacturer specifies and ask for the cylinder’s expiry date. If the ship is EU-flagged, ask whether the detector carries the wheel mark for portable gas detection (MED/3.30b).^[2][4]

SOLAS regulation XI-1/7, in force since 1 July 2016, requires ships to carry an appropriate portable atmosphere testing instrument or instruments, capable as a minimum of measuring oxygen, flammable gases or vapours, hydrogen sulphide and carbon monoxide before entry into enclosed spaces. IMO agreed guidelines in MSC.1/Circ.1477 to help select the instrument.^[1]

The regulation also requires suitable means of calibrating all such instruments, and instruments carried under other requirements may satisfy it. The German flag’s circular adds that crew with enclosed-space entry and rescue duties drill at least every two months under SOLAS III/19.3.3, and that checking and use of the instruments should be part of those drills.^[2]

Indian Register notes that a personal gas detector carried by an individual inside the space cannot be counted as the required portable atmosphere testing instrument.^[3]