These are inductive sensors sensible to metals. Two-wire non amplified D.C. sensors which contain only the oscillator and are adapted to control an electronic amplified thereshold circuit.
They are ATEX certified according to Directive 2014/34/EU. Such devices can be utilised in hazardous areas, where Gas and Air are present in the atmosphere, or Dust and Air, consistent with group II classification, categories 1G/D-2G/D or 3G/D. They also meet EN60079-0, EN60079-11, EN60079-26, IEC60079-0, IEC60079-11 and IEC60079-26 norms.