Morgan Schaffer Ltd.

9334-3275 Quebec Inc.

Stefan Voinea

Stephan Brauer

Niculae Mincu

Nicholas Lebel-Buchanan

Samuel René De Cotret

Andrew MacGillivray

Alexandre Beaudoin

Andrew Macgillivray

Samuel Rene De Cotret

An apparatus and associated a method are described for performing gas analysis on a gas sample. The method comprising exciting the gas sample with one or more electromagnetic energy sources and obtaining optical absorption signals associated with the gas sample prior to application of a catalytic process to the gas sample as well as during and/or after application of the catalytic process to the gas sample. The obtained optical absorption signals may then be processed using differential calculation approaches to derive information associated with the gas sample, which may include for example information conveying concentrations of certain specific gases in the gas sample. In some implementations, the optical absorption measurement system is configured to use the one or more electromagnetic energy sources to excite the gas sample to produce first optical absorption signals. The optical absorption measurement system is also configured to apply a catalytic process to the gas sample to derive a modified gas sample and to use the one or more electromagnetic energy sources to excite the modified gas sample to produce second optical absorption signals. Information may then be derived at least in part by processing the first optical absorption signals and second optical absorption signals. The apparatus and associated method may find practical uses in a variety of fields including, without being limited to, the field of dissolved gas analysis (DGA) for detecting/monitoring faults in liquid-insulated electrical equipment as well as equipment used for mine safety, particularly coal mines; equipment for analyzing gases that emerge from the bore hole during drilling for natural gas and oil and equipment for identifying gas leaks in underground natural gas lines as well as other areas.

Apparatus and method for performing gas analysis using optical absorption spectroscopy, such as infrared (IR) and/or UV, and use thereof in apparatus and method for performing dissolved gas analysis (DGA) on a piece of electrical equipment

A self-calibrating dissolved gas analysis apparatus and associated method are described. The dissolved gas analysis apparatus includes an analyser having an optical absorption measurement system using one or more electromagnetic energy sources to obtain optical absorption measurements associated with a gas sample. An observed response of the optical absorption measurement system is derived at least in part by using the optical absorption measurement system to obtain optical absorption measurements for a reference gas under one or more distinct moisture conditions. The derived observed response is then processed to quantify deviations between the derived observed response and an expected response and the quantified deviations are used to compensate information associated with gas concentration measurements derived by the dissolved gas analysis apparatus.

Apparatus and method for performing calibration of a dissolved gas analysis system using optical absorption spectroscopy and use thereof in an apparatus and method for performing dissolved gas analysis (DGA) on a piece of electrical equipment

A photoacoustic detector for detecting a gas which includes a resonant cavity having an inner wall capable of absorbing electromagnetic radiation and a passageway for circulating the gas through the resonant cavity. The detector also includes an electromagnetic source for generating an electromagnetic energy and an optical window associated with the electromagnetic source for introducing the electromagnetic energy into the resonant cavity towards the absorbing inner wall surface, thereby preventing the electromagnetic energy from radiating throughout the whole length of the resonant cavity. A pressure sensor is provided for detecting a pressure signal inside the resonant cavity which is representative of the gas being detected. A method is also provided for detecting a gas using the photoacoustic detector.

Photoacoustic detector

An apparatus is described for performing dissolved gas analysis on electrical equipment having components immersed in electrical insulating liquid. The apparatus comprises an analyzer including a photo-acoustic spectroscopy (PAS) measurement system for performing gas analysis on a gas sample wherein the PAS measurement system has an elongated channel including a resonant cavity and an electromagnetic energy source. The resonant cavity includes a first portion and a second portion configured for containing at least part of the gas sample, wherein the first portion defines an optical pathway configured for propagation of electromagnetic energy from the electromagnetic energy source. The resonant cavity includes an element configured for obstructing the propagation of the electromagnetic energy through to the second portion of the resonant cavity. The PAS measurement system is configured to excite a portion of the gas sample in the optical pathway to produce a photo-acoustic signal, which may then be processed to derive information associated with dissolved gas concentrations in the electrical insulating liquid. In some implementations, a pressure regulating element may be used to regulate the pressure in a gas extraction cell so that the pressure lies within a target pressure range. In some implementations, the electromagnetic energy source may be configured to produce a periodically pulsed beam of electromagnetic radiation having a chopping frequency greater than or equal to 150 Hz. One or more damper elements may be used for reducing vibrational interferences with some of the measurement equipment.

Apparatus and method for performing dissolved gas analysis on a piece of electrical equipment using resonant photo-acoustic spectroscopy and use thereof

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Brossard, Canada

Stefan Voinea