US 7,321,425 B2 | ||
Sensor and methods for measuring select components in sheetmaking systems | ||
Frank M. Haran, North Vancouver (Canada) | ||
Assigned to Honeywell International Inc., Morristown, N.J. (US) | ||
Filed on Dec. 20, 2004, as Appl. No. 11/18,167. | ||
Prior Publication US 2006/0132796 A1, Jun. 22, 2006 | ||
Int. Cl. G01J 3/28 (2006.01); G01J 3/06 (2006.01); G01J 5/02 (2006.01) |
U.S. Cl. 356—326 [356/308; 250/339.01] | 35 Claims |
1. A sensor, for measuring at least one component in a composition, that comprises:
a broadband light source that generates light;
an acousto-optic tunable filter (AOTF);
optics that direct a beam of light at the AOTF, wherein the AOTF is tuned to pass detection light having a desired wavelength
range to detect a concentration of the at least one component in the composition;
a screen that directs the detection light of known wavelength to the composition;
a detector that receives light that emerges from the composition; and
a control signal generator that provides the AOTF with at least one desired wavelength range that is characteristic of the
least one component in the composition;
wherein the composition comprises paper, and wherein the sensor detects at least one of: a level of cellulose in the paper,
a level of calcium carbonate in the paper or paper coating, a level of clay in the paper or paper coating, and a level of
latex in the paper or paper coating.
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