Analysis and quality assurance measures are inseparably interlinked. There is much more to ensuring high quality measurement results than simply the type of analytical method (standard/norm vs. operational analysis) that is used. The care taken over the individual work steps and the quality assurance/quality control (QA/QC) measures that are implemented play much greater roles. Hach® supports users of TNTplus™ Vial Tests by carrying out a substantial part of the quality assurance measures on their behalf. This means that the relevant quality and batch certificates are always available, e.g. on the Hach website. Support is also provided for users when carrying out individual quality control measures.