Submillimeter laser measurement of water or filler content of sheets and bands of dielectric material

An apparatus for measuring the moisture content of a sheet or band of dielectric material comprising:

• a submillimeter laser pumped by a single CO.sub.2 laser for outputting a beam of submillimeter wavelength radiation;
• means for scanning said beam across the width of one face of said sheet or band;
• detector means positioned opposite said sheet or band from said beam for receiving the portion of said scanning beam which is transmitted through said sheet or band and for outputting transmittance signals;
• processing means for receiving said transmittance signals and for calculating the moisture content of said sheet or band.

An apparatus for measuring the filler content of a sheet or band of dielectric material, comprising:

• at least one submillimeter laser pumped by a single CO.sub.2 laser for outputting a beam of submillimeter wavelength radiation;
• means for scanning said beam across the width of one face of said sheet or band;
• detector means positioned opposite said sheet from said beam for receiving the portion of said scanning, beam which is transmitted through said sheet and for outputting transmittance signals;
• processing means for receiving said transmittance signals and for calculating the filler content of said sheet or band of material.

An apparatus for measuring the moisture content of a sheet or band of dielectric material comprising:

• a single CO.sub.2 laser outputting a pump beam;
• at least one submillimeter laser positioned in the vicinity of said dielectric material;
• means for directing said pump beam from said CO.sub.2 laser onto said at least one submillimeter laser wherein the intensity delivered to each of said at least one submillimeter lasers is equal;
• detector means positioned opposite said sheet or band from said at least one submillimeter laser for receiving the portion of the outout of each of said at least one submillimeter laser which is transmitted through said sheet or band and for outputting transmittance signals;
• processing means for receiving said transmittance signals and for calculating the moisture content of said sheet or band;
• wherein the positioning of said at least one submillimeter laser in the vicinity of said dielectric material provides for an accommodation of moisture or pollution in the air surrounding said sheet or band so as to avoid attenuation of submillimeter wavelength radiation output from said at least one submillimeter laser.