The HBM pNRF-Reader library applies a scaling of the raw 16 bit integer values to 64 bit floating point numbers that are stored in FlexPro. This can explain, why a project database including only the data imported is about 4 times the size of the data file. If it is 10 times bigger, there may be other elements stored in the database, like computed formula results (off by default) or images of presentation objects (on by default). One can change this settings in the properties of the project database itself under the ‘General’ tab.