An apparatus for detecting one or more properties of a downhole fluid includes a housing. The apparatus also includes a location-sensitive optical detector, arranged within a chamber formed by the housing. The apparatus further includes a light source, arranged within the chamber. The apparatus also includes a lens, positioned at an end of the housing, the lens preferably having a flat side and a curved side, the flat side positioned proximate the chamber to position the flat side closer to the light source than the curved side. The apparatus further includes a mirror, arranged outside the housing.

Provided is a liquid sensor or the like that is relatively easy to manufacture. The liquid sensor includes a light emitting element, an optical waveguide, a light receiving element, and a detection circuit. The optical waveguide includes a first pillar portion, a first metal plate, a second pillar portion, and a second metal plate. The first metal plate is embedded in the first pillar portion. The second pillar portion is provided at a position opposing the first pillar portion. The second metal plate is embedded in the second pillar portion. A space for liquid is formed between the first pillar portion and the second pillar portion. The first pillar portion includes a first end surface that faces the light emitting element. The first metal plate includes a first reflecting portion that is tilted relative to the first end surface and reflects light toward the second pillar portion. The second pillar portion includes a second end surface that faces the light receiving element. The second metal plate includes a second reflecting portion that is tilted relative to the second end surface and reflects the light from the first metal plate toward the light receiving element.

An optical spectral sensing device for determining at least one property of a fluid. The device has an elongated porous body, a first end and a second end, a solid-state optical emitter at the first end of the body oriented to emit radiation toward the second end of the body, and a solid-state optical detector at the second end of the body oriented to detect radiation emitted by the optical emitter and to output a signal responsive to absorption of radiation. The device is configured to determine depth of a fluid based on the signal output by the optical detector.

An in situ near infrared sensing unit includes a housing allowing the sensing unit to be inserted in a variety of media. A transparent window is formed in the sidewall of the housing. A sensing element is mounted inside the housing. The sensing element is configured to emit near infrared light provided from a light source external to the housing, and the sensing element is configured to collect near infrared light transmitted through the transparent window. A mirror is mounted in the housing at an angle with respect to the transparent window and opposite the sensing element. The angle allows the mirror to reflect the near infrared light, emitted by the sensing element, through the transparent window.

A spectroscopic assembly may include a spectrometer. The spectrometer may include an illumination source to generate a light to illuminate a sample. The spectrometer may include a sensor to obtain a spectroscopic measurement based on light, reflected by the sample, from the light illuminating the sample. The spectroscopic assembly may include a light pipe to transfer the light reflected from the sample. The light pipe may include a first opening to receive the spectrometer. The light pipe may include a second opening to receive the sample, such that the sample is enclosed by the light pipe and a base surface when the sample is received at the second opening. The light pipe may be associated with aligning the illumination source and the sensor with the sample.

A sensor platform for the assessment of the condition and quality of fluids while in service is based on a combination of solid-state light sources (LEDs) and detectors housed within a single integrated package. The sensor platform configured to be standalone in operation and comprises interfacing optics and acquisition and processing electronics. The sensor platform is configured to obtain inputs from multiple stimulus points and correlates these to changes in the overall composition or condition of the fluid. The sensing method can be described as a combination of a differential sensor, by monitoring changes from the normal status of the fluid, and an inferential sensor where changes are interpreted in terms of global impact rather than specific localized changes in component concentration.

A sensor for monitoring the quality of oil in mechanical machinery is provided. The sensor includes a portion that is sealed from the oil which contains electric circuitry to process signals received from the sensing elements. Another portion of the sensor is exposed to the oil and contains one or more sensing elements to sense one or more properties of the oil. The sensed properties may include electrical properties, temperature properties and/or optical properties.

Provided is a liquid sensor or the like that is relatively easy to manufacture. The liquid sensor includes a light emitting element, an optical waveguide, a light receiving element, and a detection circuit. The optical waveguide includes a first pillar portion, a first metal plate, a second pillar portion, and a second metal plate. The first metal plate is embedded in the first pillar portion. The second pillar portion is provided at a position opposing the first pillar portion. The second metal plate is embedded in the second pillar portion. A space for liquid is formed between the first pillar portion and the second pillar portion. The first pillar portion includes a first end surface that faces the light emitting element. The first metal plate includes a first reflecting portion that is tilted relative to the first end surface and reflects light toward the second pillar portion. The second pillar portion includes a second end surface that faces the light receiving element. The second metal plate includes a second reflecting portion that is tilted relative to the second end surface and reflects the light from the first metal plate toward the light receiving element.

The invention relates to a method for in-situ measurement of the concentration of gaseous chemical species contained in a biogas (10) flowing in a pipe (20), for example in a biogas treatment plant or a system using biogas.

The method according to the invention is implemented by means of an optical measurement system (40) including a light source (41) and a spectrometer (44). Source (41) emits a UV radiation (42) through the biogas (10) within a measurement zone (21) in the pipe. Spectrometer (44) detects at least part of said UV radiation that has passed through biogas (10) and it generates a digital signal of the light intensity (50) as a function of the wavelength of the part of the UV radiation that has passed through the biogas. The chemical species concentration is then determined from digital light intensity signal (50).

A sensor head assembly for a measurement system for powderised agent includes: an elongate body having a proximal end configured to receive a fibre optic cable, and a distal end; a sensing chamber provided within the elongate body, a first window provided at a proximal side of the sensing chamber and a second window provided at a distal end of the sensing chamber; and a concave mirror mounted within the elongate body at a distal side of the second window, wherein the concave mirror is mounted such that its position within the elongate body is adjustable.