A facility for measuring thickness of walls of high-temperature glass containers (2) exiting forming cavities (4) and moving along a translational path (F), the facility including:
- at least first (11) and second (12) bispectral infrared cameras disposed diametrically opposite to each other on either side of the translational path (F) of the containers to receive radiation emitted by a first wall (21) of each container (2) located on a first side (I) of the container and a second wall (22) of each container located on a diametrically opposite second side, each of the at least first and second bi-spectral cameras (11, 12) delivering two images of infrared radiation of the wall of the container located in a camera field of observation in a first spectral band (λ1) in a range between 2,800 nm and 4,000 nm and in a second spectral band (2),
- the first and second spectral bands being distinct and selected such that absorption of the radiation by glass of each container is different in the first and second spectral bands (λ1, λ2) for a temperature of the containers;
- and
- at least in the first spectral band (λ1), absorption of the radiation by the glass is such that:
- the radiation measured from the first side of the container, coming from the first wall (21), is a first sum of the radiation emitted by the first wall (21) and of the radiation emitted by the second wall (22) and transmitted with absorption through of the first wall (21), such that the first sum of radiation depends on thicknesses and temperatures of the first and second walls (21, 22);
- and
- the radiation measured from the second side (II) of the container, coming from the second wall (22), is a second sum of the radiation emitted by the second wall (22) and of the radiation emitted by the first wall (21) and transmitted with absorption through the second wall (22), such that the second sum of radiation depends on the thicknesses and temperatures of the first and second walls (21, 22);
- a system (15) for driving operation of the at least first and second bispectral infrared cameras (11,12) so as to acquire simultaneously, with one of the at least first and second bi-spectral cameras (11), two images measuring intensity of the radiation of the first wall (21) in the first spectral band (λ1) and in the second spectral band (λ2) and with another of the at least first and second bi-spectral cameras (12), two images measuring the intensity of the radiation of the second wall (22) in the first spectral band (λ1) and in the second spectral band (λ2);
- and
- a computer (16) configured to determine at least thicknesses (e1, e2) of the first wall (21) and of the second wall (22), by analyzing the two images giving respectively measurements of the intensity of the radiation coming from of the first wall (21) in the first spectral band (λ1) and the second spectral band (λ2) and the two images of the second wall in the first spectral band and the second spectral band, the intensity of the radiation in the first spectral band being a sum of the radiation emitted by a wall of the container and radiation transmitted with absorption, and coming from the wall located on the other side of the container.