It has been hypothesised that generation of nitrogen during exposure by diazo duplication materials can contribute to image degradations in microform and aerial negative reproductions. Research was conducted to investigate the rate generated gas is diffused from the surface and possible film- film separations this gas may cause during contact printing. Apparatus was constructed to measure gas diffusion rates and simulated film-film separations during exposure. Diffused gas was collected in a rubber diaphragm whose expansion was measured using a variable capacitor tuned oscillator technique. To simulate printer film- film separations movement of a 5.4 x 7.5 cm. glass plate placed on the film was measured during exposure. A metal-halide mercury vapor lamp and optical system in the apparatus projected sufficient energy to destroy one half the potential density in 2.4 to 5,7 seconds. This time depended upon the type of film -10 -9 used. Measured gas diffusion rates ranged from 3.3 x 10 to 9.2 x 10 mole/sq cm/sec for the four positive working diazo films evaluated. Platefilm separations up to 2. 2- urn were measured. It was also determined that gas release is not instantaneous upon exposure and that gas continues to be diffused after exposure has terminated. In addition exposures from the top and bottom of the emulsion produce different initial gas release rates. Analytical models were developed to correlate experimental data with printer film- film separations. Measured plate-film separations were less than predicted by the models. It is believed that the models are correct and that during the plate- film separation experiments the film had an initial curl, thus violating the parallel initial zero separation condition and explaining the differences
