Comparison of our line intensities with measurements of Dopita & Hua (1997) for 11 PNe in common that are listed in Table A.1. The difference for each PNe (identified on horizontal axis) between our measurement and of Dopita & Hua (1997) is marked with a black dot using a normalised scale (vertical axis). The normalisation was done with the original errors from Dopita & Hua (1997). If the normalised absolute difference is less than 1 (dashed lines) our measurements agree within the uncertainty given by the latter authors. Open triangles present an analogous comparison for data from Acker et al. (1992) compared to Dopita & Hua (1997) for the same PNe and are given for reference.