Method for inspecting containers, wherein a fitting is applied to at least one surface region of an outer wall of a container, wherein this fitting has at least one carrier-free fitting element and preferably a plurality of fitting elements which are at least partially not connected to one another. The surface region fitted with this at least one fitting element or with these fitting elements is inspected by an inspection device and at least one characteristic value is output which is characteristic of at least one property that is characteristic of the first fitting element.

An apparatus for inspecting containers in a container treatment machine includes an optical probe, for detecting surface irregularities. The probe is formed as an optical coherence tomography probe providing in-plane resolution and/or volume resolution.

A device for detecting elevations and/or depressions on bottles, in particular in a labeling machine, the device comprising a lighting unit with a light screen for generating a light reflection on a bottle to be examined and at least one camera for detecting the light reflection. By areas of varying luminance being formed on the light screen, molding seams can be reliably detected over a large area of the bottle wall and embossings can be located in various rotational positions of the bottle. The invention also relates to a method for applying the device.

A method can include: irradiating a container with a measuring beam of an irradiation device at measurement points along a measurement direction, wherein a signal indicative of the wall thickness of the container at each measurement point is obtained by means of an optical detector, wherein by means of an evaluation device, the measurement points are compared with a reference curve that specifies the wall thickness of a reference container along the measurement direction, wherein if the comparison results in agreement between the measurement points and the reference curve it is determined that the wall thickness of the container corresponds to a predefined wall thickness and wherein if the comparison does not result in said agreement it is determined that the wall thickness of the container does not correspond to the predefined wall thickness.