Abstract: The invention provides an apparatus and a method that reduces fluid loss from a cask during a maturation process by sealably enclosing the cask in a vessel that provides an expansion volume to receive fluid vapor from the cask, a monitoring system and a method that monitors fluid loss from a cask during a maturation process using a light source and a detector to determine the presence of fluid vapor in the vicinity of the cask, a corresponding system for controlling a maturation process in which environmental conditions are controlled, and a cask leak testing system and method making use of the above.

Abstract: The invention provides an apparatus and a method that reduces fluid loss from a cask during a maturation process by sealably enclosing the cask in a vessel that provides an expansion volume to receive fluid vapour from the cask, a monitoring system and a method that monitors fluid loss from a cask during a maturation process using a light source and a detector to determine the presence of fluid vapour in the vicinity of the cask, a corresponding system for controlling a maturation process in which environmental conditions are controlled, and a cask leak testing system and method making use of the above.

Abstract: A ring laser has a cavity formed by only three elements. The first element is a concave mirror (11) which is wholly reflective to the cavity radiation but is transmissive to pump wavelength radiation. The third element is a concave mirror (13) which provides the output from the cavity. The second element is a gain element in the form of a rod (12) located in a constant axially-aligned magnetic field from a permanent magnet (14). The end faces (12A,12B) of the rod (12) are Brewster angled and additionally one such face (12B) is tilted or wedged by up to 5.degree. to make the cavity non-planar. The rod (12) is made of a material exhibiting the Faraday effect.