Abstract: In a method an an apparatus for automatic inspection of moving surfaces using at least three different illumination/observation channels, the surface to be inspected under a bright field condition is illuminated by a first beam of light from a first light source. The light of the first beam of light reemitted from the surface is received by a light sensitive sensor device to obtain a first signal. Then, the surface is illuminated under a dark field condition by a second beam of light and by a third beam of light from a second and a third light source, respectively, the first, second and third beams of light having different characteristics. The light of the second beam of light and the light of the third beam of light, respectively, reemitted from the surface are received by the light sensitive sensor device to obtain a second signal and a third signal. Finally, a physical property of the surface is derived from the first, second and third signals.

Abstract: In a method of and an apparatus for detecting three-dimensional defects in he automatic inspection of moving surfaces by means of a color vision system the surface of a moving test specimen which is to be inspected is illuminated with light of different colors simultaneously from at least two different directions, such that edges of three-dimensional defects on the surface appear with a different coloring, and on the basis of the altered coloring, at least two channels of the color image are evaluated to detect three-dimensional defects and to differentiate same from planar defects.

Abstract: The invention relates to a method for positioning a container for measurement of wear in the container lining. The method comprises taking a reference picture by a camera means of a set of at least three reference marks mounted on the container, and performing reference measurement of the container lining with a measuring device emitting and receiving optical radiation. Later, in the actual measurement situation, a measurement picture is taken of the set of reference marks with the camera means, and the actual measurement of the wear in the container lining is performed with the measurement device emitting and receiving optical radiation. By comparing the measurement situation picture with the reference picture, correction factors are calculated, on the basis of which the actual measurement of the wear in the container lining and the previously made reference measurement of the container lining are combined so as to be represented in the same coordinate system.

Abstract: A calibration method especially for calibrating a reflection spectrometric gauge, such as an oil film gauge. In the method, calibration is conducted by measuring the gauge response by means of a calibration unit and a solid, stable permanent sample (37) provided on it as a calibration sample. A change that simulates a certain substance concentration is generated by the stable permanent sample (37) in the reflection spectrum, and the gauge response is calibrated on the basis thereof. In the invention, the gauge response is calibrated by using at least two calibration samples (37, 39) having different absorption responses, said two calibration samples being said permanent sample (37) and a second calibration sample (39). For calibration, roughness compensation is performed, in which the gauge response is corrected on the basis of the measurement of the optical response of the surface to be measured and the known data on roughness dependence.

Abstract: The invention relates to a method for measuring wear in the lining of a container provided with a pivoted axle and an opening, and a container. Fixing of the coordinate systems (16, 17) of a measuring device (1) and the container (6) is performed by measuring the position of fixing points (P1, P2, P3) in the coordinate system (16) of the measuring device, whereafter the i0 lining (10) on the inner surface of the container (6) is measured. The fixing is performed by measuring the position of the fixing points (P1, P2, P3) mounted in connection with the container in the coordinate system (16) of the measuring device (1) in a situation where the opening of the container faces away from the measuring device while the measuring device is directed towards the container bottom. The container (6) is rotated around its pivoted axle (11) to a position in which the opening (9) of the container (6) faces the measuring device (1). The fixing is performed utilizing the angle difference between angle data (.alpha..sub.