Portable Apparatus (Types of Instruments)
Spot-reading or continuous duty apparatus that has been designed to be readily carried from place to place and to be used while it is being carried. A portable apparatus is battery powered and includes, but is not limited to
a) a hand-held apparatus, typically less than 1 kg, which requires use of only one hand to operate,
b) personal monitors, similar in size and mass to the hand-held apparatus, that are continuously operating (but not necessarily continuously sensing) while they are attached to the user, and
c) larger apparatus that can be operated by the user while it is carried either by hand, by a shoulder strap or carrying harness and which may or may not have a hand directed probe.
Source: IEC 60079-29-1, Explosive atmospheres – Part 29-1: Gas detectors – Performance requirements of detectors for flammable gases. Global Standards