Everything starts with preparation: identifying target flow rates, branches, and balancing dampers, checking filters and dampers, and stabilizing the AHU (Air Handling Unit). The measurements to be carried out are based on standards: NF EN 12599 for handover, NF EN 16211 for on-site airflows. NF ISO 3966 completes the set for Pitot tube exploration in closed conduits.

Also specify whether the flow rates are expressed in actual or reference conditions (Nm3/h): only values recorded under the same operating conditions and according to the same standard can be compared. The measurement methods applied will depend on the configuration of the installation.

The first control point: vents, diffusers, and grilles. The DBM620 balometer provides a direct reading of the airflow thanks to its hood, which must completely cover the terminal. With a suitably sized hood and an airtight seal, it allows for quick and effective comparison of supply and exhaust air.

With 5 hood sizes and a patented frame, the DBM620 also measures temperature, relative humidity, atmospheric pressure, and calculates the air change rate. Its ultra-compact design makes it easy to transport within technical areas, and the Pilot application completes the package. If necessary, it can also be used with Pitot tubes or a measurement grid specifically designed for supply ceilings.

In ducts, the method depends on the flow profile. With the AMI310, MP210, or VT210 equipped with a hot-wire probe, the cross-section is explored according to a grid, favoring a straight section, far from bends and dampers, to limit flow disturbances. The cross-section of the duct must be explored according to a grid adapted to its dimensions.

The MP210 and AMI310, with a pressure module coupled to a Pitot tube or DÉBIMO measuring blades, also have the ability to measure dynamic pressure to calculate the flow rate. Permanently installed in the duct, DÉBIMO blades feature pressure taps distributed at fixed positions according to the LOG-TCHEBYCHEV method. Each inspection thus uses the same sampling points. Measurement is fast, and measurement deviations related to operator positioning are reduced.

Time for balancing! On a constant volume network, with balancing dampers open, compare the measured flow / target flow ratio for each terminal. Identify the terminal with the lowest ratio and keep its damper open. Adjust the flow rates at the terminals, then the dampers, before adjusting the overall flow rate at the AHU. Then check the entire system because each adjustment modifies the pressures. Record the flow rates, deviations, methods, and instrument certificates, not forgetting the measurement uncertainty.

Specializing in all air parameters, our metrology laboratories in Montpon-Ménestérol consist of two dozen experts available to verify and calibrate all your instruments. The provided results make it possible to characterize the instruments' deviations and verify their suitability for the intended measurements.