Apparatus designed to monitor the performance of apparatus; Apparatus for long-distance microphonic monitoring; Apparatus for monitoring electrical components; Apparatus for monitoring electronic components; Apparatus for monitoring the operations of engines; Apparatus for monitoring vacuum pumps; Electric mains monitoring apparatus; Electric mains monitoring devices; Electric monitoring apparatus; Electric motor checking (monitoring or supervision) apparatus; Electrical apparatus for monitoring; Electrical instruments for monitoring sound; Electronic apparatus for monitoring machines; Electronic temperature monitors, other than for medical use; Machine monitors; Monitoring apparatus, electric; Monitoring units (electric); Monitors for recording faults; Process plant monitoring apparatus; Remote monitoring apparatus; Temperature monitors for industrial use; Temperature monitors for machines