Abstract: An alignment device having two angular degrees of freedom is provided. The alignment device is adjustable such that it is suitable for aligning a first apparatus with respect to a second apparatus. The first apparatus may emit one or more of electromagnetic waves, acoustic waves and matter towards the second apparatus and for detection by the second apparatus. The first and second apparatuses may be disposed in a harsh environment such as is found in the vicinity of an industrial process stack. In some embodiments the first apparatus is a laser, preferably a tunable diode laser, and the second apparatus is a receiver incorporating a detector. In these embodiments the apparatuses may be used to perform laser absorption spectroscopy on a process gas flowing through an industrial process stack.

Abstract: A method and system for correcting the effect of intensity fluctuations of the transmitted light in an absorption spectroscopy system used for the detection or measurement of chemical species in a medium, whereby one or more modulation bursts are imposed onto a light beam that passes through the medium. This burst signal may be obtained by modulating the bias current of a tunable diode laser, and the modulation burst signal may be optimally at the second harmonic of the modulation frequency of a wavelength modulated beam to allow usage of the same signal path processing used for the spectroscopic detection of the measurand for a second harmonic detection system.

Abstract: An alignment device, having two angular degrees of freedom is provided. The alignment device is adjustable such that it is suitable for aligning a first apparatus with respect to a second apparatus. The first apparatus may emit one or more of electromagnetic waves, acoustic waves and matter towards the second apparatus and for detection by the second apparatus. The first and second apparatuses may be disposed in a harsh environment such as is found in the vicinity of an industrial process stack. In some embodiments the first apparatus is a laser, preferably a tunable diode laser, and the second apparatus is a receiver incorporating a detector. In these embodiments the apparatuses may be used to perform laser absorption spectroscopy on a process gas flowing through an industrial process stack.

Abstract: A method and system for correcting the effect of intensity fluctuations of the transmitted light in an absorption spectroscopy system used for the detection or measurement of chemical species in a medium, whereby one or more modulation bursts are imposed onto a light beam that passes through the medium. This burst signal may be obtained by modulating the bias current of a tunable diode laser, and the modulation burst signal may be optimally at the second harmonic of the modulation frequency of a wavelength modulated beam to allow usage of the same signal path processing used for the spectroscopic detection of the measurand for a second harmonic detection system.

Abstract: This present invention relates to a device for the measurement of the amount of oxygen in a gas mixture, or other gas with significantly different magnetic susceptibility than the background gas mixture, by the use of a suspended test body in a magnetic field that experiences force due to the magnetic susceptibility of the measurand gas. In order to enable a fast time response for the system with a change in oxygen concentration, a flow regime is presented which allows a fast sweep of the measurement volume combined with adjustable, balanced pressure drops via a flow balancing element (or elements) within the flow channels to independently minimise flow related uncertainties.

Abstract: An apparatus for the measurement of the magnetic susceptibility of a gas mixture comprises: a gas sample chamber (8) adapted to receive the gas mixture; a test body (1) rotatably suspended within the gas sample chamber; magnets (10) within the gas sample chamber; a compact optical system for detecting rotation of the test body (1) including a light source (12), photodetectors (13) arranged to detect a light signal, and a mirror (5) attached to the test body (1). An actuation system is arranged to keep the test body (1) substantially at a null position. The optical system comprises at least one photodetector positioned on each side of the light source. The light source is arranged to emit a light beam towards the test body. The photo detectors are arranged to each detect an edge of a light beam reflected from the mirror.

Abstract: This present invention relates to a device for the measurement of the amount of oxygen in a gas mixture, or other gas with significantly different magnetic susceptibility than the background gas mixture, by the use of a suspended test body in a magnetic field that experiences force due to the magnetic susceptibility of the measurand gas. In order to enable a fast time response for the system with a change in oxygen concentration, a flow regime is presented which allows a fast sweep of the measurement volume combined with adjustable, balanced pressure drops via a flow balancing element (or elements) within the flow channels to independently minimise flow related uncertainties.

Abstract: An apparatus for the measurement of the magnetic susceptibility of a gas mixture comprises: a gas sample chamber (8) adapted to receive the gas mixture, and a test body (1) rotatably suspended within the gas sample chamber; means (10) for creating an inhomogeneous magnetic field within the gas sample chamber; means for detecting rotational motion of the test (body 1), comprising a compact optical system including a light source (12) and photodetectors (13) arranged to detect a light signal indicative of the rotational motion; and an actuation system (4) arranged to keep the test body (1) substantially at a null position determined by said optical system, wherein the optical system comprises at least one photodetector (13) positioned on either side of the plane which is normal to the mirror and parallel with the rotation axis of the test body, having the light source (12) positioned in the plane.

Abstract: A composite multilayer ceramic structure which comprises in a single device a plurality of layers of an electrostrictive dielectric material separated by a plurality of electrode layers in which a first portion is adapted to operate as an electrostrictive actuator and a second portion, which is adjacent to the first portion and which is not inherently piezoelectric, is adapted to operate in the same way as a piezoelectric sensor.

Abstract: A sensor assembly 1 comprises an optical fibre 4 and a transducer 23 arranged to apply transverse strain to a localised portion 24 of the fibre. Birefringence effects induced by the fibre strain are remotely sensed to obtain a signal representative of the transducer input which in turn is connected to a current sensing coil 34 thereby enabling electric current in a conductor 32 to be remotely sensed. The localised portion 24 of the fibre 4 is stripped to remove an outer jacket and is embedded in a relatively rigid matrix material. Damage to the fibre and the effects of creep are thereby avoided. The resulting sensor is particularly suited to the measurement of high currents in power distribution systems.