WHY TEST CD'S

CD Testing is not just for CD manufacturers anymore. If you are involved with the creation, duplication, replication or distribution of CD's, you can save money and prevent problems by being able to measure disc quality.

Why Test CD's?

• Data comparison does not measure disc quality.
• Just because you can read it doesn’t mean it’s good.
• Poor disc quality can cause unreliable operation and short lifetime.

All CD's incorporate very powerful error detection and correction. Data discs have an additional layer of error correction as well. This error correction is extremely effective, and CD's could not work without it, as there would be far too many errors.

However, the error correction also hides a multitude of sins. In principle, it is possible to drill a 2mm hole through the disc, and still recover every single bit! But even though this disc is readable, you could not consider it a "good" disc. It will be slow and unreliable. The data could become unrecoverable at any time.

The only way to judge the quality of the disc is to make sure it conforms to Red Book specifications. Measuring error rates also shows the location and severity of defects.

Who Sholuld Test CD's?

CD-R Duplicators

• Evaluate and Qualify CD-RMedia.
• Identify burners that are failing or about to fail.
• Discover if the problem is the media or the writer.
• Make sure the masters are good.
  
  
  Replicators

• Quality Assurance
• Production Line screening
• Conformance with License Agreement
  
  Distributors

• Manage quality variations from suppliers.
• Generate confidence in products.
• Avoid returns & unhappy customers.
• Get what you pay for.
  
  Mastering Studios
• Make sure your CD pre-masters can be mastered.
  
  End Users

• Avoid long access times.
• Increased reliability for critical applications.
• Archiving - High quality discs have longer lifetime.