A COVID-19 test method, a test apparatus and a system to control entry to an event uses particle count and spectrographic data. The present embodiments of the invention provide testing apparatuses, systems and methods. These embodiments may provide for an apparatus, system and method for non-invasive respiratory testing. Also, the embodiments may provide for a system and method for determining test sufficiency for a non-invasive respiratory testing apparatus. Also, the embodiments may provide for a system and method for permitting access to a venue for a subject.