Particle sensor and particle sensing method
AssigneeKoninklijke Philips N.V.
InventorsDeclan Patrick Kelly, Michael Martin Scheja, Shuang Chen, Cornelis Reinder Ronda
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Abstract
A particle sensing system is for sensing particles entrained in a fluid. The system comprises a flow channel having a longitudinal direction along which the fluid is to be passed, a heating arrangement for heating the fluid and thereby applying a positive thermophoretic force on the fluid in a direction perpendicular to the longitudinal direction of the flow channel and a first sensor for sensing the particles in the fluid after heating by the heating arrangement. The thermophoretic force increases the concentration of the particles at the first sensor.
Claims19
A particle sensing system for sensing particles entrained in a fluid, comprising:
- a detection volume located within a flow channel through which the fluid is to be passed in a longitudinal direction, wherein the detection volume is a sub-region of the flow channel;
- a heating element for generating a thermal gradient perpendicular to a direction of fluid flow to apply a positive thermophoretic force to particles entrained in the fluid, wherein the heating element is adjustable to provide different levels of thermophoretic force on the fluid;
- a sensor for sensing the particles in the fluid at the detection volume, wherein the positive thermophoretic force is used to constrict a space occupied by the particles within the fluid flow and thereby concentrate the particles within the detection volume;
- and
- a controller which is adapted to:
- obtain an initial particle concentration measurement with no heating;
- and control the heating element in dependence on the initial particle concentration measurement.
A method for sensing particles entrained in a fluid, the method comprising:
- passing a fluid having entrained particles along a longitudinal direction of a flow channel;
- obtaining an initial particle concentration measurement at a detection volume of the flow channel;
- heating the fluid by an amount which depends on the initial particle concentration measurement and thereby applying a positive thermophoretic force on the fluid including a component in a direction perpendicular to the longitudinal direction of the flow channel;
- and
- sensing the particles at the detection volume of the flow channel, wherein the thermophoretic force provides a constricted space occupied by the particles within a flow of the fluid and thereby increases a concentration of the particles at the detection volume, wherein the detection volume is a sub-region of the flow channel.
Dependencies are inferred from the claim text.