Temp. or humidity change monitor - holds butting ends of two optical fibres in device sensitive to temp. or humidity change and measures movements between those ends

摘要

A device to monitor temp. and/or humidity uses two optical fibres aligned together at their butt joint and a member which moves and thereby effects at least one of them; the butt join is bridged by a component with high thermal expansion and/or sensitivity to humidity; this component is fixed to the two fibres; the two fibres are held closely at their join inside a short guide in which one of the fibres can move longitudinally. When the device is used to detect temp. changes this bridging component is pref. made of low density, high density or ultra-high mol.wt. polyethylene or polycarbonate; if for humidity tests however it is pref. made of polyamide, wood or paperboard. ADVANTAGE - The device is simple at the join area.