FIELD: physics.
SUBSTANCE: apparatus for monitoring the contour of the lateral wall (30) of a vessel includes at least one light source (32, 66) for directing light energy onto the lateral wall of the vessel, and at least on optical sensor (38, 72) mounted such that it can receive light energy from the light source after reflection from the lateral wall of the vessel. The optical sensor reacts to such reflected light energy, thereby giving out signals which characterise the position of the lateral wall relative the sensor in at least three places (54, 56, 58) on the wall the vessel, spaced apart in the direction of the axis of the vessel. An information processor (40) reacts to such signals, thereby determining the contour of the lateral wall depending on the deviation of the position of the lateral wall in one of the said places from the line between positions of the lateral wall in the remaining two of the said three places. The remaining two (54, 58) of the said three places on the lateral wall of the vessel preferably lie next to the shoulder of the vessel and the base of the vessel, one position (56) lying between the shoulder of the vessel and the base of the vessel. In the preferred version, these at least three places (54, 56, 58) on the lateral wall of the vessel are normally levelled with each other in the direction parallel the axis of the vessel.
EFFECT: improved method.
8 cl, 7 dwg
