title: Single-crystal sapphire tubes as economical probes for optical pyrometry in harsh environments.
abstract: One-end-sealed single-crystal sapphire tubes are presented as a simple, robust, and economical alternative for bulky lightpipe probes. Thermal radiation from a blackbody cavity created at the inner surface of the sealed end is gathered by a simple lens-based collecting system and transmitted via optical fiber to the remote detection unit. Simplicity and applicability of the concept are demonstrated by the combination of commercially available sapphire tubes with a common optical pyrometer. Radiation thermometers with sapphire tubes as invasive probes can be useful for applications requiring immunity to electromagnetic interference, resistance to harsh environments, simple replacement in the case of failure, and enhanced mechanical firmness, enabling wider range probe positioning inside the medium of interest.
authors.affiliation: Crytur, Ltd., Palackého 175, CZ-51101 Turnov, Czech Republic.
authors.forename: Jakub
authors.initials: J
authors.lastname: Růžička
authors.forename: Jindřich
authors.initials: J
authors.lastname: Houžvička
authors.forename: Jiří
authors.initials: J
authors.lastname: Bok
authors.forename: Petr
authors.initials: P
authors.lastname: Praus
authors.forename: Peter
authors.initials: P
authors.lastname: Mojzeš