ISO specifies testing procedures for the durability of DVDs

The International Standards Organization (ISO), the International Electrotechnical Commission (IEC), and the Optical Storage Technology Association (OSTA) has specified a testing procedure to determine the durability of blank DVDs. The international ISO/IEC 10995 standard is based on the Arrhenius and Eyring methods, which describe how DVDs age relative to temperature and humidity. For example, blank DVDs age much faster at a temperature of 85°C and 85 per cent relative humidity than under normal ambient conditions. The freely available ECMA-379 standard serves as the basis for this determination.

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These measurements are, however, quite time-consuming. For instance, ECMA-379 requires measurements to be performed on 90 discs for each type of blank disc, with each disc being subjected to different temperatures and humidity levels in a climate chamber for a total of around nine months. Durability is then calculated at 25°C and 50 per cent relative humidity by means of interpolation and subsequent extrapolation. The defined limit is 5 per cent of the discs with an error rate (PI sum 8) exceeding 280.

In practice, some drives would still be able to read such discs. Furthermore, the influence of sunlight and normal wear and tear is not taken into consideration. Finally, the quality of the DVD burner used is also decisive for a disc's durability. After all, the lower the error rates during recording, the longer the discs will be readable. In the end, measurements that comply with ISO/IEC 10995 still only represent a theoretical value, though one that can at least be used to compare one blank disk to another. The new standard will be published soon.

(ehe)