Paramagnetic gas sensor apparatus and adjustment method

摘要

This present invention relates to a device for the measurement of the amount of oxygen in a gas mixture, or other gas with significantly different magnetic susceptibility than the background gas mixture, by the use of a suspended test body in a magnetic field that experiences force due to the magnetic susceptibility of the measurand gas. In order to enable a fast time response for the system with a change in oxygen concentration, a flow regime is presented which allows a fast sweep of the measurement volume combined with adjustable, balanced pressure drops via a flow balancing element (or elements) within the flow channels to independently minimise flow related uncertainties.

主权项

1. A paramagnetic gas sensor apparatus, comprising:
a body defining a chamber with at least one gas inlet and at least one gas outlet defining at least one gas flow pathway for allowing gas flow through the chamber; the at least one gas flow pathway having a first asymmetry that creates a first region of asymmetrical fluid flow; a set of magnets for creating a magnetic field within the chamber in a first direction; a test body; and a torsion balance for mounting the test body in said chamber, for rotation about an axis parallel to the direction of the magnetic field in response to a torque applied to the test body, which torque is generated in dependence on the magnetic susceptibility of a measurand gas; wherein the at least one gas inlet is arranged to supply gas to the chamber from positions at opposite sides of the chamber and in opposed directions, and at least one flow balance element provides a flow-modifying asymmetry in a gas flow pathway that creates a second region of asymmetrical fluid flow to mitigate a pressure imbalance in the vicinity of the test body that is caused by the first asymmetry.