The CD Recordable (CD-R) system gives the opportunity to write once and read many times CD information. The recorded CD-R disc is Red Book compatible, so it can be played back on conventional CD-players. The CD-R format gives the possibility for both Audio and Data recording.
In the CD-R system the disc contains recording material which shows a reflection decrease due to recording. After recording, the CD-R disc satisfies the specifications as written in the chapter DISC SPECIFICATION of the Red Book. The CD-R disc contains a wobbled pre-groove for tracking, CLV speed control and timing purposes. Recording takes place in the groove. The ECMA-394 document defines 6 types of discs allowing recording speeds up to 16x, 20x, 24x, 32x, 40x or 48x nominal CD speed using a high-speed write strategy.
The document details the specifications of recorded and unrecorded discs, the writing modes, conditions for multi-speed media testing, the requirements for CD recorders, modulation and data organization, multisesson and Hybrid discs, running OPC e.t.c.
This ECMA-396 Standard specifies an accelerated aging test method for estimating the lifetime of the retrievability of information stored on recordable or rewritable optical disks. This test includes details on the following formats: DVD-R/RW/RAM, +R/+RW and CD-R/RW. The document includes:
* stress conditions (basic stress condition and rigorous stress condition testing for use with the Eyring Method and testing for use with the Arrhenius Method) * ambient storage conditions in which the lifetime of data stored on optical media is estimated
- Controlled storage condition, e.g. 25 °C and 50 % RH, representing well-controlled storage conditions with full-time air conditioning. Eyring Method is used to estimate the lifetime under this storage condition.
- Harsh storage condition, e.g. 30 °C and 80 %RH, representing the most severe conditions in which users handle and store the optical media. Arrhenius Method is used to estimate the lifetime under this storage condition.
* evaluation system description
* specimen preparation and data-acquisition procedure
* definition of and method for estimating lifetime of stored data on specified media
* data analysis for lifetime of stored data
* reporting format for estimated lifetime of stored data
The methodology includes only the effects of temperature (T) and relative humidity (RH). It does not attempt to model degradation due to complex failure-mechanism kinetics, nor does it test for exposure to light, corrosive gases, contaminants, handling, or variations in playback subsystems.
Both standards are available for free download at http://www.ecma-international.org