Accelerated age testing


An experimental program for evaluating the likely behaviour of audiovisual materials in long-term storage or use.

Samples are exposed to various stressors such as elevated temperatures, humidity and pollutants for various time periods and evaluated for mechanical, chemical and signal-carrying properties such as base viscosity, acidity, emulsion melting point and wet strength.

Most programs are very large and require extensive analysis. The following is a short test to estimate shelf life of nitrate film.

To estimate shelf life small samples of nitrate cellulose film are heated to 140° Celsius. The heating accelerates the process of decomposition inherent in nitrate stock. The first stage of decomposition is the giving off of nitrogen dioxide gas.

At a certain point in the forced heating of the film, usually measured in minutes, the samples will have given off enough nitrogen dioxide gas to affect a pH strip. This time is then used to estimate the shelf life of a film before the onset of the decomposition process.

Measured Time Probable Shelf life
0-25 minutes 0-6 months
26-60 7-12
61-120+ 12+

Compact Discs, CD-Rs and Magneto-Optical Discs are subject to failure by a number of pathways, including photo-chemical decomposition and delamination. The hydrolytic age testing of these discs is the subject of a number of ANSI standards.