Abstract: A low temperature radiometer includes a main body, a main cavity, an exit cavity, a suspended thermometer, and an attached thermometer. The main cavity is disposed within the main body and is defined through an off-axis parabolic concentrating cone formed of the inner walls of the main body. The exit cavity is disposed within the main body and is defined through a cylindrical inner surface of the main body. The suspended thermometer is suspended within the exit cavity and is disposed to be in communication with radiation entering the main cavity and being diverted to the exit cavity. The attached thermometer is attached to the outer surface of the main body and is in thermal communication and contact with the main body.

Abstract: A low temperature radiometer includes a main body, a main cavity, an exit cavity, a suspended thermometer, and an attached thermometer. The main cavity is disposed within the main body and is defined through an off-axis parabolic concentrating cone formed of the inner walls of the main body. The exit cavity is disposed within the main body and is defined through a cylindrical inner surface of the main body. The suspended thermometer is suspended within the exit cavity and is disposed to be in communication with radiation entering the main cavity and being diverted to the exit cavity. The attached thermometer is attached to the outer surface of the main body and is in thermal communication and contact with the main body.

Abstract: A filtration material comprising a blend of at least two types of fibers: (a) polypropylene fibers and (b) either acrylic or modacrylic fibers. In a preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent modacrylic fibers. In another preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent acrylic fibers. The fibers can be blended ranging from 90:10 to 10:90 polypropylene to acrylic or modacrylic. At least one type of fibers includes an extractable agent on the outer surfaces thereof. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.

Abstract: A filter material comprising a blend of at least three types of fibers: (a) polypropylene fibers (b) polymethaphenylene isophtalamide fibers and (c) fibers of a third type selected from the group of acrylic and modacrylic. In a preferred embodiment, the blend contains about ten weight percent polymethaphenylene isophtalamide fibers, about 50 weight percent polypropylene fibers and about 40 weight percent modacrylic fibers. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.

Abstract: A filtration material comprising a blend of at least two types of fibers: (a) polypropylene fibers and (b) either acrylic or modacrylic fibers. In a preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent modacrylic fibers. In another preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent acrylic fibers. The fibers can be blended ranging from 90:10 to 10:90 polypropylene to acrylic or modacrylic. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.

Abstract: A filter material comprising a blend of at least three types of fibers: (a) polypropylene fibers (b) polymethaphenylene isophtalamide fibers and (c) fibers of a third type selected from the group of acrylic and modacrylic. In a preferred embodiment, the blend contains about ten weight percent polymethaphenylene isophtalamide fibers, about 50 weight percent polypropylene fibers and about 40 weight percent modacrylic fibers. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.