@rexc,
Let me also expand the problem. Verifying absence of particles from the groove that can cause ticks and pops is only part of the problem. The other problem is how clean are the groove wall ridges. If these ridges that at 20 kHz can be spaced at 15 to 10 microns are filled with oil/grease/debris then while there may be no pop or tick, there will be loss of high frequency detail/resolution that maybe noted as distortion or just reduced signal as the stylus fails to fully read the record. In this case, the audio file unless it is compared to the perfect file, may not detect this type of contamination.
Neil
Let me also expand the problem. Verifying absence of particles from the groove that can cause ticks and pops is only part of the problem. The other problem is how clean are the groove wall ridges. If these ridges that at 20 kHz can be spaced at 15 to 10 microns are filled with oil/grease/debris then while there may be no pop or tick, there will be loss of high frequency detail/resolution that maybe noted as distortion or just reduced signal as the stylus fails to fully read the record. In this case, the audio file unless it is compared to the perfect file, may not detect this type of contamination.
Neil