In order to test mechanical function and wear, the toner modules were tested for trouble-free operation during the yield test. In order to test the blackness, the lightness of the printouts of the modules tested was compared with that of the original modules at regular intervals and the variance was measured. In order to test the yield, the number of printed pages with the above-mentioned loss of quality was measured.

"The modules tested were used without any problems or need of additional tools; they functioned smoothly, without any detectable signs of wearing, and have no noticeable sharp corners or edges. The printouts of the modules tested show a similar or higher level of blackness than the printouts of the original modules. The modules exceeded the specified yield in this test."