Abstract: A sprayer includes a spray gun and a hopper. An air source provides compressed air to the sprayer to both eject fluid from the spray gun as a spray and to pressurize the hopper. The spray gun includes passages for providing compressed air to the nozzle for spraying and to the hopper for pressurizing the hopper. The spray gun further includes a relief valve for venting pressurized air from the hopper. The hopper receives the compressed air through a port in the hopper, and the compressed air assists the flow of material out of the hopper and into the spray gun.

Abstract: A film holder provides a lighttight environment where a film unit may be inserted while enclosed within a lighttight envelope. After insertion the envelope may be removed from the film unit to allow the exposure of the film unit by a source of electromagnetic radiation mounted on one wall of the holder. The source of electromagnetic radiation is mounted on a block to reciprocate back and forth toward the film surface to allow the source of electromagnetic radiation to press against the film unit when the envelope is retracted from the holder and the block may be withdrawn from contact with the film unit to allow the reinsertion of the envelope to cover the exposed film unit.