| 摘要 |
<p>The invention relates to a method and an arrangement for measuring and controlling the thickness of optically effective and, particularly, transparent coatings during their build-up on substrates in vacuum coating installations. The measurement is carried out by determining at least one reference value and at least one measured value for the transmission or reflection value of the coated object by using a measuring light beam, a monochromator, a photo-receiver, an amplifier and an analyzing circuit. According to the invention and for the purpose of solving the problem of enabling the measurement and display of absolute values to be carried out in the case of any required thicknesses of coating, an adjustable amplifier having an extremely linear characteristic curve is used, a first reference value is formed and stored, the degree of amplification is increased until the first reference value reaches a maximum, whereupon both the first reference value as well as the associated degree of amplification are likewise stored, a further reference value is formed, which is at a considerable distance from the first reference value and is amplified to the same degree as is the first reference value, and the actual value is then measured and is multiplied in a computer unit by the degree of amplification and is represented in dependence upon the wavelength.</p> |
