The cooling performance of a raised-floor data center isdominated by its ability to deliver adequate cooling airflowto IT equipment through perforated tiles. Although manystudies have focused on the design of plenum systems and theuse of computational fluid dynamics (CFD) to predict tileairflow rates, very little has been published regarding accuratelymeasuring airflow in existing facilities. We investigatethe ability of a commercially available passive flow hood toaccurately measure data center tile airflow and find that thebuilt-in back pressure compensation functionality does notworkwell. Further,twopreviouslyproposedcorrectionmethodsfor data center applications provide reasonable accuracywhen applied to fairly restrictive tiles, but are inaccurate forlarge-open-area tiles. As a solution, we propose a new familyof semiempirical two-measurement correction methods forpassive flow hoods. Additionally, we construct a high-accuracypowered flow hood (PFH) to validate all of the passivehoodmethods. The existing and proposed methods are evaluatedagainst bothCFDsimulations and measurementsmadein an actual data center. The correction method proposed inand recommended by this study yields the highest accuracy—less than 5% error for scenarios considered.