Abstract: A system for controlling a motor driven stage of a microscope (10) includes video camera (22) for creating a video image of a sample on the stage. A computer (12) and associated display are used to create an image of the sample on the display. Graphical markers are superimposed on the image and facilitate the identification of and subsequent acquisition of data from points at which IR data is to be obtained. Also disclosed is a method of creating a display of an area of the sample greater than that which can be viewed by the area.

Abstract: A probe for use in spectroscopic analysis comprises an optical fiber with a rod-like end piece. One form of the probe has a local detector which can be deposited on the end piece or located close to it. This improves collection efficiency of radiation diffusely scattered from a sample being investigated. An alternative arrangement uses a local source of radiation.

Abstract: A system for acquiring IR-data including a microscope with a motor drive stage (48) and a video camera (40) for creating a video image of a sample on the stage. A computer (12) and an associated display (16) are used to create an image of the sample on the display. Graphical markers are superimposed on the image and facilitate the identification of subsequent acquisition of data from points at which data is to be obtained. The markers include representations of the required aperture size and the microscope including an automatically adjustable aperture (26) which can be set under computer control to a required size at each data acquisition point.

Abstract: Interferograms produced by a Michelson type interferometer used in Fourier Transform spectroscopy are processed by an arrangement which includes an analogue-to-digital converter (12) which is sampled by a fixed frequency clock signal to provide a digital representation of the interferogram. This signal is processed by a digital data processor (18) which also receives a digital representation of the reference fringe waveform to provide a digital output representing the interferogram. The digital representation of the reference fringe waveform may be produced by a second analogue-to-digital converter or by a timer. The analogue-to-digital converter may be arranged to produce oversampled representations of the interferogram or reference fringe waveforms. In one form of the invention the analogue-to-digital converter or converters include a delta sigma modulator.

Abstract: A carrier for use in the preparation of samples for spectroscopic analysis comprises a rod-like element 10 housing a domed end 11. The dome end 11 is coated with abrasive material. To prepare a sample the abrasive material is rubbed by linear movement or rotation against the material to be analysed. That material becomes abraded and attaches to the end 11. The carrier can be formed from a commercially available dowel and is therefore easy to make and use.

Abstract: An interferometer comprises a source of radiation (10) and a beam splitter (12) for forming two beams. The beams travel along different optical paths and the optical path difference of the paths can be varies by rotatable mirror pairs M2/M3 and M4/M5. One of the paths includes an adjustable mirror M6 which is tiltable in orthogonal directions. A control unit (18) can be automatically initiate periodically an alignment procedure for aligning the interferometer.

Abstract: A Michelson-type interferometer which includes apparatus for producing a suitable collimated interferometer input beam; a beam splitter and recombiner for first splitting the input beam into two beams which have components arranged to travel along parallel forward paths and then to recombine them into a single output beam as they are returned along reverse paths to the beam splitter and recombiner; an OPD scanner for scanning the optical path difference between the two split beams travelling along said paths while substantially maintaining the parallelism between the components, and a beam reverser common to the parallel beam components for reversing their direction of travel along the reverse paths and returning them for recombination into the single output beam at the beam splitter and recombiner.

Abstract: An ATR crystal (40) for use in microscopy has a conical portion (65) for contacting a sample under investigation. The apex of the cone can be provided with a small flat surface which enables reliable and reproducible ATR analysis to be undertaken. An assembly is for mounting such a crystal.

Abstract: A carrier for use in preparing samples for spectroscopic analysis comprises a layer of abrasive material, e.g. sandpaper, created with a highly reflective material e.g. aluminium. The novel carrier reduces the effect of unwanted spectral components generated by the grit particle of the abrasive.

Abstract: A spherical sample cell (FIG. 4A) bears an external inwardly specular laye defining a hollow imaging mirror 11D and an optical aperture 11E. The mirror acts as an integrator of both the exciting radiation for irradiating the sample and the resulting excited radiation to be analysed, the former entering and the latter exiting through the aperture 11E. Optical integration resulting from multiple internal reflections provides multifold increase in excited radiation compared with bare cells, which is of particular advantage in Raman spectrophotometry. Alternatively, the mirror may be provided in two complementary halves in a two-part cell-holder, in which case any conventional sample cell that fits within the mirror may be used. Spectrophotometers adapted for use with the sample cell or the cell holder as well as methods based on them are described.

Abstract: Apparatus and methods are disclosed for lowering the temperature within a chamber from a higher actual value to a set desired lower value, the latter being stabilized by intermittently flowing liquid gas selectively through the chamber and a venting orifice, under the control of a microcomputer responding to a temperature sensor within the chamber. In one embodiment (FIG. 2), the chamber (2) and the venting orifice (11B) is supplied with coolant through separate solenoid valves (1,5) which are both open to allow maximum coolant flow rate during the initial cool-down and during the settling down stage and the approach to the steady state which follow operate with much reduced coolant flow in a coordinated intermittent mode wherein the venting orifice valve (5) is open only when extra cooling is momentarily required to assist the action of the valve (1) supplying the chamber.