Abstract: The invention relates to methods and apparatus for determining properties of a surface.

Abstract: The invention relates to methods and apparatus for determining properties of a surface.

Abstract: The invention relates to methods and apparatus for determining properties of a surface.

Abstract: Methods and apparatus for measuring particle characteristics are disclosed. In one aspect, an amount of light arising from interaction between light and a suspended sample is detected simultaneously with the acquisition of a photon count from a different direction. At least one measure of particle characteristics can then be derived based at least in part on timing between information from the steps of acquiring and detecting.

Abstract: The invention relates to methods and apparatus for determining properties of a surface.

Abstract: The invention relates to methods and apparatus for determining properties of a surface.

Abstract: A single photon counting apparatus comprising a SPAD and a controller. The controller is operable to vary the operating parameters of the SPAD during use in response to a count rate detected by the SPAD. The operating parameters comprising at least one of the voltage across the SPAD during an active period, the voltage across the SPAD during a quench period, the duration of the quench period and the temperature of the SPAD. Particle characterisation instruments comprising the apparatus are also disclosed.

Abstract: Methods and apparatus for measuring particle characteristics are disclosed. In one aspect, an amount of light arising from interaction between light and a suspended sample is detected simultaneously with the acquisition of a photon count from a different direction. At least one measure of particle characteristics can then be derived based at least in part on timing between information from the steps of acquiring and detecting.

Abstract: A reciprocating air distribution system includes a valve housing, having a cylinder therein. A valve element is slidably mounted within the cylinder. Also provided is an inlet to the cylinder, an exhaust from the cylinder and air distribution passages which are controlled by the valve element to be connected either with the intake or the exhaust. A nonmetallic gasket of thermally insulative material and thickness is between the inlet and air distribution passages on one side and the valve element and exhaust on the other. The buna elastomer has carbon black filer to make the gasket statically dissipative. The nonmetallic gasket provides channels which are part of valve control passages which are associated with a pilot valve. The valve control passages are from the inlet to both ends of the cylinder with at least one passage controlled by the pilot valve. These channels are closed by one of the components between which the gasket is located.