| 摘要 |
<p>A spectrophotometer is shown in which a deuterium lamp emits a plurality of frequencies of interest the beam passes through a filter for selecting the wavelength of the light desired to be incident onto the sample and then onto a beam splitting plate which diverts a relatively small fraction of the beam to a first reference photocell. The remaining portion of the beam then is incident directly on a sample tube. The sample tube may be so designed that its transparent walls form a lens focusing the beam on the sample to be tested. The beam then passes through the further wall of the sample tube and is detected by a second testing photocell, the output of which may be compared to the output of the reference photocell to provide a signal indicative of the relative amplitude of the testing beam. The reference photocell may be used to insure that the intensity of the beam incident on the beam splitter remains constant over time so that values output by the testing photocell may be comparable to measurements taken at a later time, without the use of a reference sample for calibration purposes. A sample cell is provided which allows the use of the instrument of the invention in on-line applications in high pressure systems. A particularly preferred method of mounting the deuterium bulb is also shown.</p> |
