Good day,
Orifice details d=92.36mm, max flow rate =120m3/hr, max diff =0-100mm wg. And my dp cell is calibrated to 0-25kpa. Is this correct cos converting 100mm wg gives me 0.98pka
Dan is absolutely correct. Most flow meter/DP transmitters have about a ten to one turn down.
Frankly I would just go ahead and buy a new transmitter. It will be less expensive in the long than all the screwing around you will have to do to get questionable results from the existing transmitter.