A method for controlling the flow of gas through a spectrometer, comprising: flowing a gas through a volume of the spectrometer, the volume being a volume through which light from a sample passes along a first path to reach a first detector and the gas being transparent to the light in a spectral region analysed by the spectrometer; transmitting light from a light source along a second path through the gas to a second detector; detecting an intensity of the light from the light source at the second detector at one or more wavelengths of the light; comparing the detected intensity of the light to a respective setpoint corresponding to a desired transmittance of the gas in the volume of the spectrometer and generating at least one error signal based on the comparison; and adjusting a flow rate of the gas through the volume of the spectrometer based on the error signal, in particular to minimise the difference between the detected intensity and setpoint.

The invention relates to an optical emission spectrometer (1) being easily adjustable, and to a method (100) to set-up and operate such a spectrometer (1) comprising a plasma stand (2) to establish a light emitting plasma from sample material, and an optical system (3) to measure the spectrum of the light (L) emitted by the plasma being characteristic to the sample material, where the optical system (3) comprises at least one light entrance aperture (31), at least one diffraction grating (32) to split up the light (L) coming from the plasma (A) and one or more detectors (33) to measure the spectrum of the light (L), wherein the plasma stand (2) and the optical system (3) are directly and fixedly mounted on respective a plasma stand flange (2B) and an optical system flange (3B) which are directly and fixedly connected to each other and wherein the optical emission spectrometer (1) further comprises an analyzing unit (34) adapted to analyze the measured spectrum and to compensate for a drift of the spectrum relative to the detector (33) potentially caused by heat transferred from the plasma stand (2) to the optical system (3) considering the thermal expansion of the optical system (3).

An aspect of some embodiments of the present invention relates to a plasma chamber for containing a solution electrode glow discharge (SEGD) apparatus, the plasma chamber comprising a hollow body and a lens. The hollow body is configured to enclose a plasma generated between a solid electrode and a solution electrode, and includes at least one viewing port for letting light generated from the plasma leave the hollow body. The lens is disposed at or near the viewing port, the lens being configured to collect light from the plasma and direct the light onto a light receiving unit.

An aspect of some embodiments of the present invention relates to a plasma chamber for containing a solution electrode glow discharge (SEGD) apparatus, the plasma chamber comprising a hollow body and a lens. The hollow body is configured to enclose a plasma generated between a solid electrode and a solution electrode, and includes at least one viewing port for letting light generated from the plasma leave the hollow body. The lens is disposed at or near the viewing port, the lens being configured to collect light from the plasma and direct the light onto a light receiving unit.

A plasma chamber for containing a solution electrode glow discharge (SEGD) apparatus, the plasma chamber comprising a hollow body and a ventilation unit. The hollow body is configured to enclose a plasma generated between a solid electrode and a solution electrode, the hollow body comprising an inlet opening, an outlet opening, and at least one viewing port for letting light generated from the plasma leave the hollow body. The ventilation unit is configured to move air from outside the hollow body into the inlet, through a portion of the hollow body located between the viewing port and a gap between the solid electrode and the solution electrode, and out of hollow body from the outlet, thereby creating an air curtain for removal from an optical path between the plasma and the viewing port of at least some vapor created by vaporization of liquid in the plasma.

A plasma chamber for containing a solution electrode glow discharge (SEGD) apparatus, the plasma chamber comprising a hollow body and a ventilation unit. The hollow body is configured to enclose a plasma generated between a solid electrode and a solution electrode, the hollow body comprising an inlet opening, an outlet opening, and at least one viewing port for letting light generated from the plasma leave the hollow body. The ventilation unit is configured to move air from outside the hollow body into the inlet, through a portion of the hollow body located between the viewing port and a gap between the solid electrode and the solution electrode, and out of hollow body from the outlet, thereby creating an air curtain for removal from an optical path between the plasma and the viewing port of at least some vapor created by vaporization of liquid in the plasma.

According to one implementation, an inflammable spark estimation system includes: a photodetector for measuring intensity of discharge light arising from a spark arising from a structural object made of a plurality of materials; and a data processing system configured to determine whether the spark has inflammability, based on the intensity of the discharge light measured by the photodetector, with referring to determination information. The determination information has been determined based on features of waveforms of wavelength spectra of possible discharge light arising from possible inflammable sparks respectively arising from possible materials of which the structural object may be made. The data processing system is configured to further determine which of the plurality of the materials the spark has arisen from, based on the intensity of the discharge light measured by the photodetector, with referring to the determination information, when the spark has been determined to have the inflammability.

Systems and methods are disclosed for using downhole plasma discharge effects to determine porosity and/or permeability of formation material. In some embodiments, a method includes determining a concentration of at least one chemical reaction product in a drilling fluid that has interacted with a plasma discharge proximate formation material. A relation between arc and spark of the plasma discharge is determined based, at least in part, on the at least one chemical reaction product, and at least one of porosity and permeability of the formation material is determined based, at least in part, on the relation between arc and spark.

A device for generating a plasma and detecting a light signal. The plasma being intended to be generated in the vicinity of a study area of a sample and the light signal originating in the study area. The device including a current generator, an analysis unit, and an electrical and optical waveguide including means for transmitting an electric current configured to generate a plasma at one end of the means for transmitting the electric current in the vicinity of the study zone, means for detecting and transmitting configured to detect and transmit the light signal from the study area to the analysis unit, and an optical cladding portion, the means for transmitting the electric current and the means for detecting and transmitting the light signal being accommodated in the optical cladding portion.

A device for generating a plasma and detecting a light signal. The plasma being intended to be generated in the vicinity of a study area of a sample and the light signal originating in the study area. The device including a current generator, an analysis unit, and an electrical and optical waveguide including means for transmitting an electric current configured to generate a plasma at one end of the means for transmitting the electric current in the vicinity of the study zone, means for detecting and transmitting configured to detect and transmit the light signal from the study area to the analysis unit, and an optical cladding portion, the means for transmitting the electric current and the means for detecting and transmitting the light signal being accommodated in the optical cladding portion.