Patent ID: 11959878
Assignee: SOUTHWEST RESEARCH INSTITUTE
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 5:
6. A method of detecting concentrations of particles in a gas or gas mixture containing particles, all collectively referred to as a “gas”, comprising:
delivering the gas to a sensor comprising a flow tube, the flow tube having an inlet and an outlet, and having a pair of electrodes arranged such that at least a portion of the gas flows from the inlet to the outlet in a direct path within the flow tube and between the electrodes;
applying increasing voltages to the electrodes as the gas flows through the electrodes;
measuring response data from the electrodes representing current values between the electrodes while the gas is between the electrodes;
processing the response data to determine a concentration of particles in the gas, by analyzing a signature representing only a portion of a voltage-current profile, namely a transition to voltage breakdown after a saturation regime; and
wherein the electrodes are a distance apart that is predetermined based on detection of signatures of an expected range of sizes of particles.