Browse Prior Art Database

Purged FTIR Sample Chamber

IP.com Disclosure Number: IPCOM000050511D
Original Publication Date: 1982-Nov-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Cadwallader, RH: AUTHOR [+2]

Abstract

In some FTIR (Fourier Transform Infrared) spectrometers, a sample chamber must be opened to place a sample within a precisely located fixture at the focal point of a beam of IR energy. Access to the sample chamber is through a cover or door, and upon opening the door, a vacuum or nitrogen purge within the spectrometer deteriorates. The operator must wait a period of time, after operating the door, to again vacate or purge the system before the next test can begin.

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Purged FTIR Sample Chamber

In some FTIR (Fourier Transform Infrared) spectrometers, a sample chamber must be opened to place a sample within a precisely located fixture at the focal point of a beam of IR energy. Access to the sample chamber is through a cover or door, and upon opening the door, a vacuum or nitrogen purge within the spectrometer deteriorates. The operator must wait a period of time, after operating the door, to again vacate or purge the system before the next test can begin.

Shown in the drawing is an improved sample chamber which avoids the above difficulties. The figure is a schematic vertical sectional view through a sample chamber 10. An IR beam 1, shown in dotted lines, is focused at the central part of the chamber. Two cone shaped shrouds 2 on either side of the focal point are rigidly mounted upon sample chamber walls 3. Shrouds 2 extend to a sample-holding mechanism 4 which locates a sample 5 being tested at the focal point of the beam. Thin potassium bromide (KBr) crystals or other suitable windows 6, which are transparent to the IR energy, are sealed across shrouds 2 to withstand vacuum or pressure at either side of the shrouds. Nitrogen inlets 7 are located near windows 6 and introduce pressurized nitrogen into the shrouds. The nitrogen prevents windows 6 from fogging to thereby extend the window life and allow maximum beam energy to pass through the windows. In addition, the flow of nitrogen from the shrouds is towards the sample and c...