A recent report on the ARS website, documents the achievement of scientists at the Egg Safety and Quality Research Unit and the Quality and Safety Assessment Research Unit located at the Richard Russell Center in Athens, Ga.

The teams have developed a test instrument to detect micro cracks in shells. The research projects follows a request from USDA-Agriculture Marketing Service to develop a unit to determine the prevalence of cracks which may not be visible on either candling or using high-frequency analysis crack detectors as installed on commercial egg graders. 

The system comprises a chamber in which eggs are subjected to negative pressure and are then scanned with an electronic camera to detect cracks. Using 1000 commercial eggs, the system detected 99.4% of cracks with only a 0.3% false positive rate. The sensitivity and specificity of the negative pressure unit exceeds the parameters attained by trained observers.

It is apparently the intention of USDA-AMS to deploy the unit if it can be economically commercialized to assist in grading of eggs.