A particle characterization apparatus comprising: a light source for illuminating a sample with a light beam; a detector arranged to detect scattered light from the interaction of the light beam with the sample; and a focus tuneable lens arranged to collect the scattered light for the detector from a scattering volume and/or to direct the light beam into the sample.

A particle characterization apparatus is disclosed comprising: a sample cell for holding a sample, a light source for producing a light beam for illuminating the sample in the sample cell, thereby producing scattered light by the interaction of the light beam with the sample; a focussing lens for focussing the light beam within the sample; and a detector for detecting the backscattered light along a detection optical path that intersects the focussed light beam within the sample. The intersection of the light beam and the detection optical path in the sample define a detection region. The apparatus comprises an optical arrangement for varying the volume of the detection region.

Methods and systems are provided for foreign object debris monitoring in an environment with a dynamic debris field, such as an environment for operating an aircraft. The debris monitoring technique includes generating a light beam and dispersing it to create a virtual witness plate, which is a two-dimensional sheet of light that covers a detection area. The technique also include detecting scattered light from the virtual witness plate caused by debris passing through it. A debris event may be generated based on the scattered light, indicating the presence of debris in the detection area.

An inspection system utilizing an air scatter standard includes one or more illumination sources to generate a beam of illumination, illumination optics configured to focus the beam of illumination into a volume of air contained within a chamber of an inspection chamber, one or more collection optics configured to collect a portion of illumination scattered from the volume of air, a detector configured to receive the collected portion of illumination from the one or more collection optics, a controller including one or more processors, communicatively coupled to the detector, configured to execute a set of program instructions to receive one or more signals from the detector and determine a state of the beam of illumination at one or more times based on a comparison between at least one of the intensity or polarization of the illumination scattered from the volume of air and a predetermine air scatter standard.

A particle characterisation apparatus comprising: a light source for illuminating a sample with a light beam; a detector arranged to detect scattered light from the interaction of the light beam with the sample; a focus tuneable lens arranged to collect the scattered light for the detector from a scattering volume and/or to direct the light beam into the sample, a sample holder with an opposed pair of electrodes and configured to hold a sample in position in a measurement volume between the pair of electrodes such that a planar surface of the sample is aligned orthogonally to the electrode surfaces, the planar surface adjacent to the scattering volume, wherein adjustment of the focus tuneable lens results in adjustment of the relative position of the planar surface and the scattering volume by moving the scattering volume.

An inspection system utilizing an air scatter standard includes one or more illumination sources to generate a beam of illumination, illumination optics configured to focus the beam of illumination into a volume of air contained within a chamber of an inspection chamber, one or more collection optics configured to collect a portion of illumination scattered from the volume of air, a detector configured to receive the collected portion of illumination from the one or more collection optics, a controller including one or more processors, communicatively coupled to the detector, configured to execute a set of program instructions to receive one or more signals from the detector and determine a state of the beam of illumination at one or more times based on a comparison between at least one of the intensity or polarization of the illumination scattered from the volume of air and a predetermine air scatter standard.

A particle characterisation apparatus comprising: a light source for illuminating a sample with a light beam; a detector arranged to detect scattered light from the interaction of the light beam with the sample; a focus tuneable lens arranged to collect the scattered light for the detector from a scattering volume and/or to direct the light beam into the sample, a sample holder with an opposed pair of electrodes and configured to hold a sample in position in a measurement volume between the pair of electrodes such that a planar surface of the sample is aligned orthogonally to the electrode surfaces, the planar surface adjacent to the scattering volume, wherein adjustment of the focus tuneable lens results in adjustment of the relative position of the planar surface and the scattering volume by moving the scattering volume.

A particle characterization apparatus comprising: a light source for illuminating a sample with a light beam; a detector arranged to detect scattered light from the interaction of the light beam with the sample; and a focus tuneable lens arranged to collect the scattered light for the detector from a scattering volume and/or to direct the light beam into the sample.

A particle characterization apparatus is disclosed comprising: a sample cell for holding a sample, a light source for producing a light beam for illuminating the sample in the sample cell, thereby producing scattered light by the interaction of the light beam with the sample; a focussing lens for focussing the light beam within the sample; and a detector for detecting the backscattered light along a detection optical path that intersects the focussed light beam within the sample. The intersection of the light beam and the detection optical path in the sample define a detection region. The apparatus comprises an optical arrangement for varying the volume of the detection region.

The present disclosure relates to a sensor arrangement for determining the turbidity of a liquid medium. The sensor arrangement includes a sensor section with at least one light source for sending transmission light into a measuring chamber, and at least one receiver associated with the light source for receiving reception light from the measuring chamber, wherein the transmission light is converted into the reception light in the measuring chamber by the medium by means of scattering at a measurement angle, and the reception light received by the receiver is a measure of the turbidity. The reception light is back reflected at a reflection element in contact with the medium, whereby an optical path from the light source through the measuring chamber to the reflection element and from the reflection element through the measuring chamber to the receiver results.