Method of measuring the amount of substance associated with a material in the presence of a contaminant

A method of measuring the amount of a substance associated with a sheet material in the presence of a contaminant, said contaminant having an electro-magnetic radiation absorption characteristic different from the electromagnetic radiation absorption characteristic of said substance, wherein said method comprises the steps of:

• emitting a first band of electro-magnetic radiation, wherein said first band lies outside an absorption band of said substance, and lies within an absorption band of said contaminant;
• directing said first band to impinge said material;
• detecting said first band after transmitting through said material,
• generating a first signal, in response to said first band detected;
• generating a second signal corresponding to the intensity of the first band detected without material;
• emanating a second band of electromagnetic radiation, wherein said second band lies within an absorption band of said substance, and also lies within an absorption band of said contaminant;
• directing said second band to impinge said material;
• receiving said second band after transmitting through said material;
• generating a third signal, in response to said second band received;
• generating a fourth signal corresponding to the intensity of the second band received without material;
• and
• calculating the amount of substance in accordance with the formula:
• ##EQU5## where A, B, C are calibration constants;
• M=intensity of second band received without material divided by intensity of second band received with material;
• N=intensity of first band detected without material divided by intensity of first band detected with material.

A method of measuring the amount of water associated with a paper material in the presence of carbon, wherein said method comprises the steps of:

• emitting a first band of electromagnetic radiation, wherein said first band lies outside the electromagnetic absorption band of water but lies within the electromagnetic absorption band of carbon;
• directing said first band to impinge said paper material;
• detecting said first band after reflecting from said paper material;
• generating a first signal, in response to said first band detected;
• generating a second signal corresponding to the intensity of the first band detected without material;
• emanating a second band of electromagnetic radiation, wherein said second band lies within the electromagnetic absorption band of water and lies within the electromagnetic absorption band of carbon;
• directing said second band to impinge said paper material;
• receiving said second band after reflecting from said paper material;
• generating a third signal, in response to said second band received;
• generating a fourth signal corresponding to the intensity of the second band received without material;
• and
• calculating the amount of water in accordance with the formula:
• moisture=A+B(M+1/M)-C(N+1/N)
• where
• A, B, C are calibration constants;
• M=intensity of second band received without material divided by intensity of second band received with material;
• N=intensity of first band detected without material divided by intensity of first band detected with material.

A method of measuring the amount of water associated with a paper material in the presence of carbon, wherein said method comprises the steps of:

• emitting a first band of electromagnetic radiation, wherein said first band lies outside the electromagnetic absorption band of water but lies within the electromagnetic absorption band of carbon;
• directing said first band to impinge said paper material;
• detecting said first band after transmitting through said paper material;
• generating a first signal, in response to said first band detected;
• generating a second signal corresponding to the intensity of the first band detected without material;
• emanating a second band of electromagnetic radiation, wherein said second band lies within the electromagnetic absorption band of water and lies within the electromagnetic absorption band of carbon;
• directing said second band to impinge said paper material;
• receiving said second band after transmitting through said paper material;
• generating a third signal, in response to said second band received;
• generating a fourth signal corresponding to the intensity of the second band received without material;
• and
• calculating the amount of water in accordance with the formula:
• ##EQU6## where A, B, C are calibration constants;
• M=intensity of second band received without material divided by intensity of second band received with material;
• N=intensity of first band detected without material divided by intensity of first band detected with material.