The EasyIO FW-VAV flow balancing objective is to create a 3-point scale factor.

If you take into account the differential pressure, a non-calibrated flow offers a 1-point
scale factor, from the zero flow to the K-factor.

Note: The
K-factor is presented the as flow rate at 1.0 in. WC or 250 pascals.

Figure 1. Default non calibrated flow sensor showing the 1-point scale factor.

During the calibration process, the system captures the differential pressure to use it as an additional scale point to calculate the new scale factor. That differential pressure captured during the minimum or maximum flow calibration process is the measured flow rate pressure. When the balancing command returns to auto mode, the actual flow is calculated based on the new scale factor.

Figure 2. Calibrated flow sensor

Taking into account the differential pressure, a calibrated flow offers a 3-point scaling factor: from the zero flow to the minimum flow, from the minimum flow to the maximum flow, and from the maximum flow to the K-factor.