| 摘要 |
<p>PURPOSE: To measure the extent of deterioration of oil accurately regardless of the individual difference among detectors by providing means for blocking the incidence of infrared rays on an infrared detector for the time required for measurement or longer. CONSTITUTION: After chopping infrared rays, an optical path switching plate 15 switches the optical path to 1) block incidence of the infrared rays on detectors 24, 26, 2) pass the infrared rays through a sample cell 21 thence through the detectors 24, 26, or 3) pass the infrared rays through a reference cell 20 thence through the detectors 24, 26. The switching is made at an interval longer than the time required for effecting accurate measurement through the detectors 24, 26. Background value of the detector is then subtracted from the outputs of the detectors 24, 26 obtained by measuring the infrared rays passing through the sample cell and the reference cell. The corrected value is compared the values passed through the sample cell and the reference cell for each output from the detectors 24, 26 thus determining the extent of deterioration of oil.</p> |
