Velocity-integrated intensities of the traditional dense-gas tracers HCN(1−0), CS(2−1), HNC(1−0), and HCO⁺ (1−0) as a function of H₂ column density. Left panels: original uncorrected data. Right panels: data after applying the correction factors described in Appendix D.2 to simulate emission at a constant temperature of 10 K. Note the decrease in dispersion and the better agreement between clouds after the temperature correction. The data are color-coded as in previous figures: blue for California, green for Perseus, and red for Orion A. The dashed line in the top panels represents a linear trend for comparison.