Linear Velocity Measurements Research Articles

The measurement of mass flow and linear velocity of a gas by continuous ionization

A theoretical and experimental investigation has been carried out to evaluate the characteristics of the continuous ionization method of gas-flow measurement when the radioisotope source is mounted upstream of the detector. The particular advantage of this system is that it can be used to measure mass flow. A formula has been derived which gives the collector current in terms of the ion density at the source position, ion transit distance, ion recombination coefficient, the pressure drop in the test section and the gas velocity. This formula, which has been confirmed experimentally over a particular flow range, can be used for design studies. It is also shown how the range of linear velocity but not of mass flow, can be extended by increasing the pipe diameter.

Instantaneous linear velocity of flow in pulmonary artery measured by a catheter tip method.

Measurements of the instantaneous linear velocity of blood flow in the pulmonary artery of the human have not been reported previously. This report describes a catheter tip method for making such measurements.