Hello,

Other than P&T compensation for dry gases, are "density meters" being used to make mass flow measurement by DP flow elements? (say an insertion type).This would be meaningful especially for large bore pipes where Coriolis.

A thermal mass flow measurement is also heavily dependent on the physical properties of the gas, most important of all the molecular weight. (assuming it is dry so humidity not to be an issue in this case).

The reason is we "calculate" the DP across the element (orifice, nozzle, venturi, etc.) but if the assumed molecular weight or gas composition is incorrect, all the calculated flow would be incorrect. How about using a real time actual density meter.

A multivariable transmitter still uses P&T compensation so I am looking at if having a separate insertion type density meter (rather than assuming the molecular weight is what we thing really is) can be used or not. I know it is not common, but why not and what are the pros and cons?

Thanks for your thoughts.