How can increase the range for DP flowmeter (orifice plate, venturi, pitot, annular) for example:

FT-010, DP Range: 0 to 2500 mmH2O Flow Range: 0 to 600 m3/h, Orifice plate BETA: 0.6961.

I need increase flow range measurement 0 to 1000 m3/h so recalculate DP Range and the new DP Range is 0 to 6944.4 mmH2O

This procedure is correct for liquid and gas? what is the possible maximun and minimun flow range?

the accuracy is afected? what parameters should be considered? have standard or guide?