Abstract: Apparatus for analysing a liquid sample (194) comprises beam generating means (1) for generating electromagnetic radiation, detector means (8) for detecting electromagnetic radiation from the beam generating means after the radiation has interacted with the sample, and sample retaining means (10) for releasably retaining sample in the path of the beam. The sample retaining means comprises a hydrophobic surface (for example, a coating on a plate 118) on which the sample is, in use, supported. There is also disclosed a method of performing photometric or spectrophotometric analysis of a liquid sample by sandwiching samples between two opposed hydrophobic support surfaces, passing a beam of electromagnetic radiation through one of the surfaces and then through the sample, and analysing the beam after it has passed through the sample.

Abstract: Apparatus for analysing a liquid sample (194) comprises beam generating means (1) for generating electromagnetic radiation, detector means (8) for detecting electromagnetic radiation from the beam generating means after the radiation has interacted with the sample, and sample retaining means (10) for releasably retaining sample in the path of the beam. The sample retaining means comprises a hydrophobic surface (for example, a coating on a plate 118) on which the sample is, in use, supported. There is also disclosed a method of performing photometric or spectrophotometric analysis of a liquid sample by sandwiching samples between two opposed hydrophobic support surfaces, passing a beam of electromagnetic radiation through one of the surfaces and then through the sample, and analysing the beam after it has passed through the sample.

Abstract: An intrusion detector for a vehicle, such as the trailer of a tractor-trailer combination. The detector, which is attachable to the vehicle, includes a carbon dioxide detector responsive to the concentration of carbon dioxide in a compartment of the vehicle. The intrusion detector generates an alarm if the carbon dioxide concentration in the compartment exceeds a predetermined level.

Abstract: A gravity separator for the separation of heavier particles from lighter waste material comprises a stack of decks (4) mounted for resonant oscillatory motion within a supporting frame (1). A motor (9) oscillates the decks at their resonant frequency while a distribution system (6) supplies a feed in the form of a slurry to the surface of the decks. As shaking continues, the heavier particles within the slurry are gradually separated from the lighter particles. Optimal separation is provided by a control system which, if necessary, automatically changes the amplitude of oscillation and/or the timing of the stages as separation proceeds, for example in response to outputs of detectors which measure the frequency of oscillation and the power being consumed.