| 摘要 |
<p>An apparatus for measuring optical characteristics of liquid samples, clinical samples for example, has an optical head (21) which is adapted to scan past a rack (12) of sample containers first in one direction and then in the opposite. The optical head has reference and test light sources (22) and corresponding light detectors (28) and separate optical paths are provided in the head for developing reference and test beams passing through the scanned samples. A fixed band pass filter is provided in the reference path and a filter wheel with a plurality of different band pass filters is provided in the test path, the apparatus being arranged to index the requisite filter into the test path in dependence upon the results of the reference scan. The optical head is driven by a reversible stepper motor (26) via a toothed drive belt (27) and this enables the output signals from the detectors to be correlated to the specific samples in the rack. The reference and test signals from the detectors are processed so that signal aberrations due to artefacts (e.g. scratches) in the sample containers are neglected, and results are derived dependent upon both the reference and test scans and are printed out on an integral printer. The apparatus is compact (it can be fitted into a briefcase) and requires no special skills for its utilization, being programmable for performing specific tests of a predetermined kind by use of an integral bar code reader.</p> |
