Sensor and methods for measuring select components in sheetmaking systems

A sensor, for measuring at least one component in a composition, that comprises:

• a broadband light source that generates light that is directed to the composition;
• an acousto-optic tunable filter (AOTF) positioned to receive light that emerges from the composition, wherein the AOTF is tuned to pass detected light having a desired wavelength range to detect a concentration of the at least one component in the composition;
• a detector that receives the detected light;
• 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.

A method for measuring an amount of at least one component of a composition tat comprises the steps of:

• directing broadband light to an acousto-optic tunable filter (AOTF);
• tuning the AOTF to pass first detection light having a desired wavelength to detect a concentration of a first component in the composition;
• directing the first detection light to the composition;
• detecting an intensity of the first detection light that emerges from the composition;
• tuning the AOTF to change the wavelength of the detection light to generate second detection light to measure a second component in the composition;
• directing the second detection light to the composition;
• detecting an intensity of the second detection light that emerges from to composition;
• and
• determining an amount of at least one of the components of the composition using the intensities of the first and second detection light;
• wherein the composition comprises paper, and wherein determining the amount of at least one of the components comprises detecting 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.

A method for measuring an amount of at least one component of a composition that comprises the steps of:

• directing broadband light to the composition;
• directing light that emerges from the composition into an acousto-optic tunable filter (AOTF);
• tuning the AOTF to pass first detection light having a desired wavelength to detect a presence of a first component in the composition;
• detecting an intensity of the first detection light that emerges from the composition;
• tuning the AOTF to change the wavelength of the detection light to generate second detection light to measure a second component in the composition;
• detecting an intensity of the second detection light that emerges from the composition;
• and
• determining an amount of at least one of the components of the composition using the die intensities of the first and second detection light;
• wherein the composition comprises paper, and wherein determining the amount of at least one of the components comprises detecting 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.