Two quality-assurance plots (data from \pp collisions recorded in 2015 with all supermodules installed, tracks with at least 70 TPC clusters and $\pt>0.5$\gevc). Left: Efficiency of matching tracklets to TPC tracks. Right: Mean number of layers per track in each stack (cf.\ the discussion of inactive chambers in Section \ref{Chapterhvinbeam}). | ![](https://alice-publications.web.cern.ch/sites/default/files/papers/3740/cali-match-90289.png ) ![](https://alice-publications.web.cern.ch/sites/default/files/papers/3740/cali-ntrkl-90293.png ) |