MFDigital CD DVD Information Library
Thursday, June 24, 2004
CD Manufacturing > Quality Assurance > Mechanicals Tests
Mechanical Tests and measurements include:
- Radial Noise to determine the lateral tracking drift from the center of the pits being scanned.
- Eccentricity calculates the accuracy of the center hole.
- BLER is the Block Error Rate before any error correction take place.
- E22 measures uncorrected errors correctable by error concealment.
- E32 is a measure of uncorrectable errors and should be zero.
- Track Pitch which should be between 1.5 to 1.7 microns.
- Scan velocity which should be between 1.2 and 1.4 m/s.
- BLI (begin of lead-in) should be at a maximum radius of 23 mm.
- BPL (begin of program area), should be at radius 24.8mm to 25mm.
- BLO (begin of lead-out) must not exceed radius 58.
These measurements are made at the same time as the electrical signals are measured.