ISO 19891-1:2017提供了有关性能、待测量气体、灵敏度、指示、警报级别、防震、温度和进水保护的规范，以及在船舶进入密闭空间之前用于密闭空间大气测试的便携式气体探测器的测试要求。 ISO 19891-1:2017规定了符合SOLAS法规XI-1/7“封闭空间大气测试仪器”的合适便携式气体探测器，并可用于确定市场上可用的便携式气体探测器是否适合符合这些SOLAS要求。 注1 SOLAS规则XI-1/7要求在2016年7月1日之前在船上携带适当的便携式大气测试仪器。SOLAS法规要求，在进入封闭空间之前，至少应配备能够测量氧气、易燃气体或蒸汽、硫化氢和一氧化碳浓度的适当便携式大气测试仪器。 为了测量易燃气体或蒸汽的浓度，本文件将易燃气体指定为“甲烷”或“丙烷和丁烷”，并要求明确标记可通过便携式气体探测器测量的易燃气体类型。便携式气体探测器无法测量或检测未标记的易燃蒸汽/气体。 注2:在测量丙烷和丁烷时，异丁烷是便携式气体探测器的替代标定气体。 ISO 19891-1:2017未给出易燃气体毒性的任何指示。

ISO 19891-1:2017 provides specifications on performance, gases to be measured, sensitivities, indications, alarm levels, protection against shock, temperature and water ingress, and testing requirements of portable gas detectors used for atmosphere testing of enclosed spaces onboard ships prior to entry into those spaces. ISO 19891-1:2017 specifies suitable portable gas detectors for compliance with SOLAS regulation XI-1/7 "Atmosphere testing instrument for enclosed spaces", and may be used for deciding whether portable gas detectors available on the market are suitable for compliance with these SOLAS requirements. NOTE 1 SOLAS regulation XI-1/7 requires appropriate portable atmosphere testing instrument or instruments to be carried onboard ships, by 1 July 2016. The SOLAS regulation requires, as a minimum, the appropriate portable atmosphere testing instrument or instruments to be capable of measuring concentrations of oxygen, flammable gases or vapours, hydrogen sulphide and carbon monoxide prior to entry into enclosed spaces. For the purpose of measurement of concentrations of flammable gases or vapours, this document specifies the flammable gas as either "methane" or "propane and butane", and requires clear marking of types of flammable gases which can be measured by the portable gas detectors. Flammable vapours/gases which are not marked cannot be measured or detected by the portable gas detector. NOTE 2 Iso-butane is an alternative calibration gas of portable gas detectors in measuring propane and butane. ISO 19891-1:2017 does not give any indication of toxicity of the flammable gases.