If I have ultrsoinc meter for gas and the flow range are (320-10000)m3/h and I calibration in the lab from (320-6400)m3/h. So is that ok or not and why. Because in AGA9 report recommended to do calibration from min.to max.
Can help me plz
That is a question for the cal. lab, too many specifics.
In all likelihood it is okay.
Now you need to consider the meter function. If for custody transfer or a sales contract, then you have to read the contract specifics and talk with the purchaser of the gas...
The question can only be answered by the accurracy requirements you have to meet.
Typically they are defined by the person asking for calibration and the calibration results presented by your calibration lab.