Abstract: A hollow container defining a sample chamber is formed of at least two parts which fit together and have apertures therein. One of the parts is displaceable relative to the other part between a first relative disposition of the parts in which the apertures are open so as to provide a clear path for air to pass through the container and a second relative disposition of the parts in which the apertures are closed so that there is no path for air to pass through and a volume of air is trapped in the chamber. In one embodiment part is axially moveable relative to the other part. In another embodiment where the parts are tubular, one of the parts is rotatable relative to the other.

Abstract: A hollow container defining a sample chamber is formed of at least two parts which fit together and have apertures therein. One of the parts is displaceable relative to the other part between a first relative disposition of the parts in which the apertures are open so as to provide a clear path for air to pass through the container and a second relative disposition of the parts in which the apertures are closed so that there is no path for air to pass through and a volume of air is trapped in the chamber. In one embodiment part is axially moveable relative to the other part. In another embodiment where the parts are tubular, one of the parts is rotatable relative to the other.

Abstract: Sensing apparatus based on the use of Raman spectroscopy for detecting the presence and location of a species of interest in a medium comprises a light transmissive optical fibre (4) with an elongate sensing length along at least a portion thereof, a light source means (1) for transmitting pulses of light along the fibre, and a detector (6) for detecting at the same end of the fibre as the light source Raman signals resulting from species (c) of interest at the interface of the sensing length and a medium in which it is located. The time difference between the transmission of an excitation pulse and detection of a Raman emission signal caused by that pulse is determined, and is used to determine the position of the species along the fibre.

Abstract: A slippage sensor comprises a light-transmissive elastic component (14) defining an object-contactor face (15), input and output light guide (16a, 16b) defining a light transmission path through the component, and an indicator (19) connected with the output guide to detect transmission variations caused by elastic deformation of the component due, in turn, to relative slipping movement of an object (10) contacted thereby. In one form of sensor the input/output guides define a light path discontinous at the contactor face and to be completed by a surface (13) of the object as a reflector. In another form the component carries a reflector deformable therewith. In a further form the component is photoelastic and the input/output guides include polarisers. The sensor is useful to indicate when a minimum object gripping force is attained or it can indicate object characterisation.