Patent ID: 6809825
Filing Date: 2004-10-26
Classification: G01N

Abstract:
A gas permeable probe for use in an optical analyzer for an exhaust gas stream flowing through a duct or chimney, the probe comprising:an elongate hollow structure having a length and including first and second ends and a side wall, with an optical cavity defined between said first and second ends within said side wall, a mounting structure at said first end and adapted for mounting said elongate hollow structure within said duct or chimney, a support member at said second end, a connecting structure connecting said mounting structure at said first end to said support member at said second end, an optical window at said first end permitting a beam of light originating from an optical analyzer to enter into said optical cavity to travel from said first end to said second end, a filter module having a filter forming a part of said side wall, said filter module being removable from said connecting structure in a direction transverse to the length of the elongate hollow structure, and a retroreflector provided at said second end for returning said light beam to said first end of said hollow structure and being releasably connected to said support member, said optical window being releasably mounted at said first end of said elongate hollow structure between said mounting structure and said filter module, there being a first heater associated with said optical window and a second heater associated with said retroreflector.