Identify exactly what was measured
A check starts with the name of the quantity, not the number of rows in a record. Air velocity, volumetric flow rate, pressure differential and rotational speed describe different characteristics. If a conclusion concerns air supplied to a room, the materials must show the connection between the quantity actually measured and that indicator. A neatly formatted table does not itself establish that connection.
The reviewer compares the designation, unit, measurement location and comparison criterion. For example, the flow through a recirculating unit cannot be treated as outdoor airflow without explanation. A unit's factory rating does not become an on-site measurement either. Values obtained from the design, data sheet and calculation are identified separately: mixing these sources can create the appearance of a check that was never actually performed.
Reconstruct the sequence of operating modes
A measurement series may contain readings taken under different settings. The measurement times, control system state, valve positions and operation of related systems are therefore checked. If the main duct was measured first, adjustments were then changed and grilles were examined only afterwards, combining those results into one balance requires separate justification.
The entry ‘equipment switched on’ does not describe the operating mode in sufficient detail. Control logs, controller setpoints, actual fan speed and servicing events are useful. Panel photographs are compared with the record's timing rather than treated as universal confirmation of the entire series. If the mode changed automatically, the reviewer checks whether this variability was considered. Missing information cannot be replaced retrospectively with an assumption that the system operated identically throughout.
Compare locations with the system geometry
The measurement point number must appear on a diagram, and the diagram must identify the actual measurement location. For a duct, the internal cross-sectional dimensions, point positions and nearby flow-disturbing elements are checked. A list of identical velocities without coordinates does not establish whether a profile was examined or the instrument was held in one convenient position.
Particular attention is given to the transition from point values to a mean. The averaging used must correspond to the points' positions and the parts of the cross-section they represent. For a flow hood, suitability for the particular terminal and necessary corrections are checked. If the selected section did not meet the method's conditions, the reviewer explains the consequence: which indicator could have been distorted and why greater instrument accuracy alone does not resolve this shortcoming.
Check the calculation through to the final row
Airflow is often a calculated quantity. Checking it requires original readings, cross-sectional area, formulas and unit conversions. The reviewer traces the calculation for each disputed point, checks transfer of data to the summary table and identifies which quantities were added. A unit conversion error or incorrectly selected area can affect the result more than rounding the final digits.
Even if an instrument displays flow directly, it is still necessary to establish which dimensions, coefficients and processing mode were entered. Pressure-based conversions depend on the relationship adopted and its applicability to the installed equipment. A missing printout does not always prevent checking if sufficient primary data survive; a final number without those data does not make the calculation reproducible.
Assess uncertainty and the effect of the shortcoming
Current verification or calibration information is important but does not describe the entire uncertainty of a result. Instrument range and resolution, repeatability, geometry, corrections and the method's characteristics all influence it. Repeating a reading many times does not remove systematic bias caused by a poorly chosen point. The report must make clear which influences were assessed and which were left outside the calculation.
When a result is close to a requirement limit, the decision rule is checked. Measurement uncertainty and the tolerance for a system characteristic have different meanings and cannot arbitrarily replace one another. The review's outcome links each shortcoming to a specific conclusion. Retained data sometimes allow a table to be recalculated, whereas an unknown operating mode or unsuitable measurement location may require a new series. Reviewing a document does not create missing on-site readings.