Abstract: An elongated tape for marking underground lines having a cross-woven scrim formed by a first plurality of elongated plastic fibers disposed parallel to the axis of elongation of the tape and a second plurality of elongated fibers disposed normal to the fibers of the first plurality. Preferably, the tensile strength of the second plurality of fibers exceeding the tensile strength of the first plurality of fibers. The scrim is coated with a layer of plastic to form a surface, and a sign is disposed on the surface. If the tape while buried encounters a digger, it tends to break transversely rather than along the axis of elongation leaving the sign legible. In one embodiment, a layer of electrically conducting foil is disposed on one side of the scrim.

Abstract: A photon calorimeter (20, 40) is provided that comprises a laminar substrate (10, 22, 42) that is uniform in density and homogeneous in atomic composition. A plasma-sprayed coating (28, 48, 52), that is generally uniform in density and homogeneous in atomic composition within the proximity of planes that are parallel to the surfaces of the substrate, is applied to either one or both sides of the laminar substrate. The plasma-sprayed coatings may be very efficiently spectrally tailored in atomic number. Thermocouple measuring junctions (30, 50, 54) are positioned within the plasma-sprayed coatings. The calorimeter is rugged, inexpensive, and equilibrates in temperature very rapidly.