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US 7,847,943 B2Granted
Web measurement device
AssigneeABB AB
InventorsAke Hellstrom, Rambod Naimi, Michael O'Hora
Life of this patent
Estimating the term…
Abstract
A sensor is provided that measures web caliper using optical and magnetic measuring devices. The optical measuring devices may employ a confocal chromatic aberration method to accurately determine the distance to the moving web and the magnetic devices may be ferrite core coil and target. Means of stabilizing a moving web are included for improving dynamic measurement accuracy.
Claims19
A sensor for monitoring the attributes of a moving web, the sensor comprising:
- a sensor head positioned adjacent a moving web;
- an optical sensor probe, positioned in said first sensor head, and including an objective lens having an axial chromatism;
- a spectrograph in communication with the objective lens to receive a reflected signal from the moving web, said spectrograph being adapted to measure the spectral width of said reflected signal and determine a web surface characteristic therefrom.
A sensor for monitoring a moving web, the sensor comprising:
- a first sensor head positioned on a first side of the moving web;
- a second sensor head positioned on a second side of the moving web, opposed to said first side;
- a first optical sensor probe positioned in said first sensor head including an first objective lens having an axial chromatism;
- a second optical sensor probe positioned in said second sensor head and including a second objective lens having an axial chromatism;
- a spectrograph in communication with said first and second objective lens to receive a reflected signal from the moving web, said spectrograph being adapted to measure the spectral width of said reflected signals and determine a surface characteristic of said first surface and said second surface.
2 more elements
A method of measuring a moving web, the method comprising:
- positioning an optical sensor probe adjacent to the moving web, said optical sensor probe having an objective lens having an axial chromatism;
- transmitting light through the objective lens toward the moving web;
- receiving a reflected signal through the objective lens;
- determining a spectral width of the reflected signal;
- determining a web surface characteristic based on the spectral width;
- and
- displaying the web surface characteristic.
4 more elements
Dependencies are inferred from the claim text.