Measurement of characteristics of gas mixt. in petrochemical plant - compares pressure difference across calibrated nozzle at constant flow with those of standard gas mixts.

摘要

A pressure-difference method allows on-line measurement of the physical characteristics e.g. density, volumetic mass, means molecular mass, of a gaseous mixt. containing hydrogen. The mixt. is passes at constant flow rate through a calibrated orifice and the pressure difference across the orifice is measured. A calibration measurement uses the same flow rate of air at atmospheric and ambient temp. Further calibration measurements at the same flow rate using gas mixts. of known physical characteristics. The appts. comprises a pump, a differential manometer of the liquid column type and a nozzle.