Meter for measuring brightness of bleached fibers and controlling the bleaching process

Claim 2

An apparatus as recited in claim 2 including filters intermediate said light sources and said phototubes.

Claim 3

An apparatus for continuously controlling the bleaching of fibers and for continuously measuring and recording the brightness of light reflected from said bleached fibers comprising, a bleaching tank, means for feeding fibers to said bleaching tank, means for feeding bleaching agent to said tank, means for discharging bleached fibers from said tank, a drum, a means for forming said bleached fibers onto a mat on said drum, a housing open at one end and closed at its sides and opposite end, roller means for supporting said housing on said mat with said open end of said housing facing said mat, a first light source in said housing, a second light source in said housing, a first light-responsive phototube in said housing, a shielding box affixed to one side of said housing such that the side of said housing forms one wall of the shielding box, a second light-responsive phototube in said shielding box, an aperture in said wall of said housing which forms part of the shielding box, a reflecting means affixed to the internal portion of the housing in close juxtaposition to the shielding box aperture in said housing, said reflective means being situated intermediate second light source in said housing and the open end of the housing to direct a portion of the unreflected light from the second light source to the second light-responsive phototube to serve as a reflecting standard, means in said housing for directing reflected light from said mat at the open end of said housing to said first phototube, means for comparing the electrical signal from said first light-responsive phototube to the signals from said second light-responsive phototube to yield a comparative measurement of the reflectivity of the bleached fibers, means responsive to said comparative measurement for recording the brightness of said mat, and means responsive to said comparative measurement for controlling said means for feeding bleaching agent to said tank. 5. An apparatus as recited in claim 4 including a first light filter intermediate the open end of said housing and first phototube and a second light filter intermediate said means for reflecting a portion of the light from said second light source and said second light source.