Abstract: A sample cell includes a cell body having a proximal end, a distal end, a circumference, and a sample holding surface on the proximal end, an o-ring around the circumference, a cap disposed over the proximal end of the cell body, the cap forming a seal with the o-ring, and a window in the cap located at an adjustable distance from the sample holding surface.

Abstract: A spectrometer collects background spectra during the idle time in which it is not collecting spectra from a sample. These spectra are collected over a range of exposure times, allowing the background reading on each pixel to be modeled as a function of exposure time. When sample spectra are then collected, the exposure time for the sample spectra can be used with the modeled function to compute an estimated background within the sample spectra. The estimated background can then be subtracted from the sample spectra, thereby reducing the noise therein.

Abstract: Alignment of multiple beam paths in a microscope such as a Raman spectrographic microscope utilizes an alignment instrument that is mounted on the stage of the microscope and positioned by the operator until an aperture of the alignment instrument is at an intended focal point of the microscope. A light source within the alignment instrument is turned on to project light through the aperture which is passed on a return light beam path to the input aperture of a spectrograph where it is detected. Features are included in the return beam path to adjust the beam path until the light detected is maximized, thereby aligning the return beam path to the intended focal point. The light source in the alignment instrument is turned off and a light source in the microscope system, such as a laser, is activated to provide an illumination light beam on a beam path that extends through the objective lens of the microscope, which focuses the beam onto the alignment instrument.

Abstract: Alignment of multiple beam paths in a microscope such as a Raman spectrographic microscope utilizes an alignment instrument that is mounted on the stage of the microscope and positioned by the operator until an aperture of the alignment instrument is at an intended focal point of the microscope. A light source within the alignment instrument is turned on to project light through the aperture which is passed on a return light beam path to the input aperture of a spectrograph where it is detected. Means are provided in the return beam path to adjust the beam path until the light detected is maximized, thereby aligning the return beam path to the intended focal point. The light source in the alignment instrument is turned off and a light source in the microscope system, such as a laser, is activated to provide an illumination light beam on a beam path that extends through the objective lens of the microscope, which focuses the beam onto the alignment instrument.

Abstract: A gas sample collection device and method for cold trapping individual gas bands from a gas source that may include a chromatographic separation and for spectrographically analyzing the individual gas bands. The device includes a vacuum chamber containing a rotatably supported highly thermally conductive transmissive substrate having a highly thermally conductive support axle and at least one transmissive surface for holding a sample deposited thereon. A gas inlet is provided for depositing a mixture of sample and matrix material on the transmissive surface which is maintained at a sufficiently low temperature to cause solidification of the gas. A first set of optical elements directs an incident beam of electromagnetic analytical radiation from a source onto the solidified deposit, while a second set of optical elements directs the portion of incident beam transmitted through the deposit and substrate to a detector that is sensitive to the spectral wavelengths being investigated.

Abstract: A thermogravimetric analysis flow cell interface unit has an elongated tubular cell body, glass inlet and outlet transfer lines integrally connected to the cell body for flowing a gas therethrough, a window element for allowing passage of an infrared radiation beam into and out of the cell body, and a mirror element for reflecting the radiation beam back through the cell body. The mirror element and the window element are assembled to the cell body in such a manner that the entire unit may be quickly disassembled and reassembled for easy cleaning and replacement. The flow cell assembly is adapted to interface a thermogravimetric analyzer and an infrared spectrometer.