Source: MSC.1/Circular.1477 – Guidelines to facilitate the Selection of Portable Atmosphere Testing Instruments for Enclosed Spaces as required by SOLAS regulation XI-1/7 (approved 2014), circular and annex, paragraphs 1 to 18.
Reference: imorules.com – MSC.1/Circ.1477
Each set contains 10 different multiple-choice questions drawn from this circular.