Loops checks should be done as part of SCADA set-up. Then calibration might also be done (for critical attributes). The calibration will check the scaling and consistency of the data. For non-calibrated probes, and verification should be done for each point.
Incorrect scaling is a common error in SCADA set-up. Scaling is similar to a correction factor, or a conversion between a signal and a read-out.
It is acceptable and more efficient to test scaling and probe readout during commissioning (not qualification) since correcting an error during commissioning is much easier and often without QA oversight - since commissioning is often an engineering/start-up activity.