Pretty large difference spot meassurement between Flir i7 and E4

[luis garcia]

I have performed some simple tests comparing the readings of Flir i7 and E4 cameras using center spot measurement.

Brightness and emisivity settings are set in both cameras to 0.95 and 20C.
The measurements I get on i7 give always readings that are 2C  above E4. I have tried over different distances and surfaces.

Can this offset be normal or I am missing something here ?

P.S. I know the accuracy of these cameras is rather poor (about 2C according to E4 specifications). But I am wondering why there are such differences bewteen both cameras.