| 摘要 |
<p>1,069,910. Monitoring coating apparatus. KALLE A. G. Sept. 28, 1964 [Oct. 1, 1963J, No. 39434/64. Heading G1A. In order to measure the amount of a coating material deposited on a carrier web electromagnetic radiation is directed on to the coated web and the transmitted or reflected rays divided so that radiation of a kind absorbed by the coating material produces an output from one photo-cell and radiation not, or only slightly, absorbed gives an output from a second photo-cell. The difference or ratio of the two outputs is an indication of the amount of coating present and may be recorded and/or used to control the coating plant. The radiation source may be a discharge tube giving lines of adequate intensity for each of the required beams. Radiation leaving the test web is preferably collected by lenses and directed by half-silvered mirror 7 on to the photo-cells 5 and 6. Frequency selective elements may be associated with the mirror 7 and/or cells at 8 and 9. Calibration may be effected by using an attenuator in one of the cell outputs, by the introduction of rotatable polarizing filters in front of the cells or by partially inserting a colour filter into the undivided beam. In the latter case the apparatus may be arranged to automatically check its calibration against a standard and readjust the filter positioning as necessary.</p> |
