Abstract: Gas cells and systems for absorption spectroscopy, and methods thereof. The method involves providing a channel with an inlet for receiving a gas sample and an outlet for releasing the gas sample from the gas cell; providing first and second end components with an optically transparent portion, each of the end components is configured to minimize a difference between a temperature of the optically transparent portions and an internal temperature of the channel; mounting the first end component the channel so that the optically transparent portion is positioned for receiving an incident beam into the channel; and mounting the second end component to the channel opposite from the first end component so that the optically transparent portion is positioned for permitting optical transmission into and out of the channel.

Abstract: A gas cell assembly and applications of the gas cell assembly in absorption spectroscopy. An example gas cell assembly includes a gas cell body with an inlet for receiving a gas sample from a gas source; a first and a second end portions that allow optical transmission into and out of the body, the second end portion being substantially opposite from the first end portion; and a channel providing a path for the gas sample and optical beam(s) between the first end portion and the second end portion. The gas cell assembly also includes reflective surfaces outside the body to receive versions of the optical beams from the body and to reflect each version of the incident beam towards the body. A detector, then, receives a last reflected beam and transmits a corresponding data signal to a processing unit for analyzing the gas sample based on the data signal.

Abstract: Gas cells and systems for absorption spectroscopy, and methods thereof. The method involves providing a channel with an inlet for receiving a gas sample and an outlet for releasing the gas sample from the gas cell; providing first and second end components with an optically transparent portion, each of the end components is configured to minimize a difference between a temperature of the optically transparent portions and an internal temperature of the channel; mounting the first end component the channel so that the optically transparent portion is positioned for receiving an incident beam into the channel; and mounting the second end component to the channel opposite from the first end component so that the optically transparent portion is positioned for permitting optical transmission into and out of the channel.

Abstract: A gas cell assembly and applications of the gas cell assembly in absorption spectroscopy. An example gas cell assembly includes a gas cell body with an inlet for receiving a gas sample from a gas source; a first and a second end portions that allow optical transmission into and out of the body, the second end portion being substantially opposite from the first end portion; and a channel providing a path for the gas sample and optical beam(s) between the first end portion and the second end portion. The gas cell assembly also includes reflective surfaces outside the body to receive versions of the optical beams from the body and to reflect each version of the incident beam towards the body. A detector, then, receives a last reflected beam and transmits a corresponding data signal to a processing unit for analyzing the gas sample based on the data signal.

Abstract: A gas cell assembly and applications of the gas cell assembly in absorption spectroscopy. An example gas cell assembly includes a gas cell body with an inlet for receiving a gas sample from a gas source; a first and a second end portions that allow optical transmission into and out of the body, the second end portion being substantially opposite from the first end portion; and a channel providing a path for the gas sample and optical beam(s) between the first end portion and the second end portion. The gas cell assembly also includes reflective surfaces outside the body to receive versions of the optical beams from the body and to reflect each version of the incident beam towards the body. A detector, then, receives a last reflected beam and transmits a corresponding data signal to a processing unit for analyzing the gas sample based on the data signal.

Abstract: Methods and apparatuses for improved process control in metal smelting through measurement of off-gas profiles in real time. A tunable laser source is projected across a volume of off-gas and detected to provide a real time profile of gas concentrations. The real time gas concentration profile may be compared with known profiles to identify problems in the smelting process or to identify when the process is complete.

Abstract: The present invention relates to a method and apparatus for detecting transitions between different gas or liquid products in a flow path and, more particularly, it relates to an apparatus and method utilizing Raman spectroscopy for detecting transitions between petroleum products. A Raman spectrometer is preferably to produce a monochromatic excitation beam at a wavelength of approximately 670 nm. The spectrometer consists of an entrance slit, a combined diffraction grating/focussing element, and an exit slit. The Raman signal, which exits the spectrometer exit slit is detected by a highly sensitive photomultiplier tube, and sent to a computer device for data acquisition and analysis. The proposed invention detects liquid or gas products in a flow path by detecting the changes in the composition of various petroleum products flowing through a gasoline pipeline, by means of exposing samples of various petroleum products to the Raman spectrometer system.

Abstract: The present invention relates to a method and apparatus for detecting transitions between different gas or liquid products in a flow path and, more particularly, it relates to an apparatus and method utilizing Raman spectroscopy for detecting transitions between petroleum products. A Raman spectrometer is preferably to produce a monochromatic excitation beam at a wavelength of approximately 670 nm. The spectrometer consists of an entrance slit, a combined diffraction grating/focussing element, and an exit slit. The Raman signal, which exits the spectrometer exit slit is detected by a highly sensitive photomultiplier tube, and sent to a computer device for data acquisition and analysis. The proposed invention detects liquid or gas products in a flow path by detecting the changes in the composition of various petroleum products flowing through a gasoline pipeline, by means of exposing samples of various petroleum products to the Raman spectrometer system.

Abstract: An apparatus for use in Differential Optical Absorption Spectroscopy (DOAS) or in other optical apparatus provides a moveable or oscillating aperture. It has a sensor for detecting the position of the aperture, and a drive for oscillating the aperture; the drive and sensor can comprise coils forming a linear variable differential transformer, and the aperture can be spring biased to a neutral position. A control circuit is connected between the coil or other sensor and the drive coils, so that the motion of the aperture follows a desired profile. This enables significant parts of the apertures motion to be constrained to be linear. The aperture can be provided in a shuttle mounted on extension arms, whose ends are connected to resilient biassing means which serve both to support the shuttle and to bias it. More preferably, extension arms extend through pole pieces of magnets, which provide a magnetic field for drive coils.