Method for calibrating a thickness gauge

Abstract

A method for calibrating a thickness gauge, wherein the thickness gauge measures the thickness of a measurement object in a predefinable measuring direction (Z), comprising at least one displacement sensor (1, 2) operating in a contactless or scanning manner, wherein a reference object (3) having a known thickness and shape is moved into at least a partial region of the measurement field of the at least one displacement sensor (1, 2), comprises the following steps with respect to particularly precise and simple calibration. First, at least two independent measurement values are recorded by the at least one displacement sensor (1, 2) in at least two predefinable sites on a first surface of the reference object (3) at predefinable times tj, or as a function of predefinable positions pj of the reference object (3) in the measurement field, where j = 1, 2... Then the tilting or spatial position of the reference object in the measurement field is determined based on the measurement values recorded at the times tj, or as a function of the positions pj of the reference object (3). Then, a further measurement value is recorded by the at least one displacement sensor (1, 2) at a further site located in the measuring direction (Z) on a second surface disposed opposite the first surface, or on a surface region of the reference object (3) disposed opposite the first surface, in order to determine a thickness value of the reference object (3) in the measuring direction (Z).

Description

technical field [0001] The invention relates to a method for calibrating a thickness measuring device, wherein the thickness measuring device measures the thickness of a measured object in a preset measuring direction, the thickness measuring device has at least one non-contact or scanning displacement sensor, wherein A reference object of known thickness and shape is moved into at least one local area of ​​the measurement field of the at least one displacement sensor. Background technique [0002] DE 40 11 717 A1 discloses a method for calibrating a thickness measuring device with two non-contact or scanning displacement sensors, in which a reference object of known thickness is moved into the measuring field of the displacement sensors. According to this known method, two sensors measure the distance from the top and bottom of the reference object to the top or bottom of the reference object, for example, in a predetermined measuring direction. The thickness of the refere...

AI Technical Summary

Problems solved by technology

[0004] In order to ensure precise calibration and measurement, therefore, not only the reference object but also the measured object must be guided exactly in parallel, which is difficult or often impossible in practice

[0005] Another disadvantage of this known method is that even slight differences in the thickness of the reference objects, e.g. due to surface roughness or local unevenness, can distort the calibration results

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