The text was revised. Each single measurement was based on internally averaged of 50 spectra (3 times). Each sample was measured from four positions (90°rotating the Petri dish each time). Consequently, 4 rotation x 3 time = 12 spectra were obtained. It is one of the commonly used method and several references are available. Line;252-259 Line 176: “…resulted 50 spectra…”.
Line 191, 365: “…with different gaps and segment sizes.” “…with gap segment size of…”.