Fig. (2) Semi-logarithmic plot used for the conversion of raw Canary Numbers (rCN) to normalized CNs for a universal 0 - 100 scale. CNs are determined from measured rCNs using the equation, CN(i) = a(i)ln[rCN(i)] + b(i), where CN(i) = Normalized Canary Number (an output value); rCN(i) = Raw Canary Number measured by The Canary System (an input value); i = 1 (Z₁, healthy, CN = 0-20); i = 2 (Z₂, suspicion of early caries, CN = 21-70); and i = 3 (Z₃, suspicion of advanced caries, CN = 71-100). The coefficients “a(i)” and “b(i)” are the slope and y-intercept of the line in Zone (i), respectively. The variables “a(i)” and “b(i)” are unique to each zone.