Abstract: A system for monitoring the passage of people through a controlled location, the system comprising: a security access device for selectively allowing and preventing the passage of one or more people through the controlled location; an array of imaging sensors which, in use, emit a curtain of light and detect reflected light from people through the curtain of light to generate image data; and, processing means for analysing characteristics of the reflected image data for each sensor in the array and controlling the operation of the security access device in dependence on the analysis, wherein the processing means determines at least one of the following characteristics for the array of sensors; duration of signal from each sensor, number of signals for each sensor and the saturation of the array.

Abstract: The present invention relates to chromatography, and provides in a chromatography column new end fittings and an insert. Each end fitting is a plastics plug which is screwed to the end of the column tube, and inside the end fitting is a shoulder which is engaged by an insert. The insert fits neatly into the column tube so that it can be used to press against the column packing. The insert also embodies a cavity for a frit, and the end of the insert which projects into the column and seats against the column packing, has a skirt which is flared so that the pressure inside the column will spread the skirt which is of flexible plastics material into sealing contact with the column inner wall forming an effective seal. The insert may be in one piece plastics material component, or it may be in two pieces, a plastic piece embodying the skirt and stainless steel piece has the portion which engages the shoulder.