Population diagrams of CH₃OD and CH₂DOH using the 30 m data of Mauersberger et al. (1988) and Jacq et al. (1993), respectively. The old CH₂DOH effective line strengths of Jacq et al. (1993) (upper panel) and the new ones (lower panel) were used in the calculations. The beam filling factor was taken into account by assuming a source size of 15′′. The rotational temperatures and column densities were estimated by a least-squares fit, and the results and uncertainties are given in the diagrams. For CH₂DOH, the red dashed line in the upper panel indicates the fit with a fixed temperature of 100 K as adopted by Jacq et al. (1993) and the one in the lower panel the fit with a temperature of 130 K (the same as the CH₃OD temperature derived here).