Abstract: A pressure sensing assembly (1), comprising: an elongate, axially extending tube (100), having a flexible tube wall (102) that encloses an inner pressure chamber (106); and at least one sensor unit (200), including: two tube wall fixation devices (210), connected to the tube wall (102) at respective axially spaced apart positions, and configured to fix respective diameters (D, d) of the tube wall at said positions; and a first strain sensing element (220), connected to the tube wall (102) at a first position axially in between said two tube wall devices (210), and configured to provide a first signal indicative of an axial elongation of the tube wall resulting from a change in axial curvature of the tube wall when a pressure differential between the inner pressure chamber (106) and an outside environment (108) of the tube is applied across the tube wall at said first position.

Abstract: Operation of an oil-water separator or other liquid mixture separator is monitored. The separator uses a vessel through which a mixture of different liquid components flows horizontally. A plurality of ultrasound transducers is provided on a wall of the vessel at different heights at a common stage along the direction of the horizontal flow. Ultrasound at a plurality of different ultrasound wavelengths is transmitted through the vessel between transducers and ultrasound arriving transducers is detected. Parameter values of a model are fitted to the detection. A model is used that relates height dependent properties of liquid in the vessel to properties of the detected ultrasound transmission between transceivers, the model comprising at least a fittable parameter of a height dependent droplet size distribution in a least a sub-range of a height of liquid in the vessel. The model relating the droplet size distribution to ultrasound wavelength dependence of the properties of ultrasound transmission.

Abstract: A pressure sensing assembly (1), comprising: an elongate, axially extending tube (100), having a flexible tube wall (102) that encloses an inner pressure chamber (106); and at least one sensor unit (200), including: two tube wall fixation devices (210), connected to the tube wall (102) at respective axially spaced apart positions, and configured to fix respective diameters (D, d) of the tube wall at said positions; and a first strain sensing element (220), connected to the tube wall (102) at a first position axially in between said two tube wall devices (210), and configured to provide a first signal indicative of an axial elongation of the tube wall resulting from a change in axial curvature of the tube wall when a pressure differential between the inner pressure chamber (106) and an outside environment (108) of the tube is applied across the tube wall at said first position.

Abstract: Operation of an oil-water separator or other liquid mixture separator is monitored. The separator uses a vessel through which a mixture of different liquid components flows horizontally. A plurality of ultrasound transducers is provided on a wall of the vessel at different heights at a common stage along the direction of the horizontal flow. Ultrasound at a plurality of different ultrasound wavelengths is transmitted through the vessel between transducers and ultrasound arriving transducers is detected. Parameter values of a model are fitted to the detection. A model is used that relates height dependent properties of liquid in the vessel to properties of the detected ultrasound transmission between transceivers, the model comprising at least a fittable parameter of a height dependent droplet size distribution in a least a sub-range of a height of liquid in the vessel. The model relating the droplet size distribution to ultrasound wavelength dependence of the properties of ultrasound transmission.

Abstract: An optical apparatus includes an illumination system configured to form a pulsed radiation beam, an optical element with a surface on which the radiation beam is incident in operation, and a gas source arranged to supply a mixture of a first type of gas and a second type of gas to a space adjacent the surface. Particles of the first and second types of gas are capable of reacting with the surface, when activated by the radiation beam. The gas source is configured to generate a combination of surface occupation numbers of molecules of the first and second types of gas on the surface under operating conditions, at least prior to pulses of the radiation beam, the combination of surface occupation numbers lying in a range in which reactions of particles with the surface during pulses of the radiation beam are in majority reversed.

Abstract: An optical apparatus includes an illumination system configured to form a pulsed radiation beam, an optical element with a surface on which the radiation beam is incident in operation, and a gas source arranged to supply a mixture of a first type of gas and a second type of gas to a space adjacent the surface. Particles of the first and second types of gas are capable of reacting with the surface, when activated by the radiation beam. The gas source is configured to generate a combination of surface occupation numbers of molecules of the first and second types of gas on the surface under operating conditions, at least prior to pulses of the radiation beam, the combination of surface occupation numbers lying in a range in which reactions of particles with the surface during pulses of the radiation beam are in majority reversed.