US 11,959,878 B2
Gas and particle sensor using voltage and current behavior between electrodes during glow-to-arc transition
Maher Abdulhamid Aldayeh, Helotes, TX (US); and Imad Said Abdul-Khalek, San Antonio, TX (US)
Assigned to Southwest Research Institute, San Antonio, TX (US)
Filed by Southwest Research Institute, San Antonio, TX (US)
Filed on Oct. 13, 2022, as Appl. No. 17/965,129.
Application 17/965,129 is a division of application No. 16/733,574, filed on Jan. 3, 2020, granted, now 11,506,631.
Prior Publication US 2023/0097032 A1, Mar. 30, 2023
Int. Cl. G01N 27/70 (2006.01)
CPC G01N 27/70 (2013.01) 10 Claims
OG exemplary drawing
 
1. A sensor for detecting concentrations of particles in a gas or gas mixture containing particles, all collectively referred to as a “gas”, comprising:
a flow tube having an inlet and an outlet;
a pair of electrodes within the flow tube, arranged such that at least a portion of the gas flows from the inlet to the outlet along a direct path within the flow tube and between the electrodes; and
a controller operable to apply increasing voltages to the electrodes as the gas flows between the electrodes and to measure response data from the electrodes representing current values between the electrodes while the gas is between the electrodes;
wherein the controller is further operable to process the response data to determine a concentration of particles within 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;
wherein the electrodes are a distance apart that is predetermined based on detection of signatures of an expected range of sizes of the particles.