| 摘要 |
The invention relates to a method for measuring, by interferometry, the thickness (s) of the transparent wall (16) of a container (12) made of a thermoplastic material, which comprises: a first step of emitting, from a light source (34), perpendicularly to the transparent wall (16) of the container (12), a light ray (E) having a continuous spectrum, the ray (E) emitted being partially reflected by the external face (18) of the wall (16) and then by the internal face (20) of the wall (16); and a second step of spectrometric analysis, using an interferometric sensor (38) of the interference produced by the superposition of the first and second reflected rays (R1, R2), the interference resulting in a periodic variation in the light intensity (I) of the light wave as a function of frequency (1/?), the variation having a period (P) that is proportional to the thickness (s) of the wall (16) of the container (12).
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