US 11,796,510 B2
Acoustic resonance chamber
Lowell Kolb, Rapid City, SD (US); Charles Tolle, Rapid City, SD (US); Nathan Williams, Rapid City, SD (US); and Jason Ash, Rapid City, SD (US)
Assigned to SOUTH DAKOTA BOARD OF REGENTS, Pierre, SD (US)
Filed by South Dakota Board of Regents, Pierre, SD (US)
Filed on Apr. 30, 2021, as Appl. No. 17/246,093.
Application 17/246,093 is a division of application No. 16/270,447, filed on Feb. 7, 2019, granted, now 11,029,284.
Claims priority of provisional application 62/628,182, filed on Feb. 8, 2018.
Prior Publication US 2021/0255144 A1, Aug. 19, 2021
Int. Cl. G01N 29/036 (2006.01); G01N 29/24 (2006.01); G01N 29/024 (2006.01); G01N 29/22 (2006.01)
CPC G01N 29/036 (2013.01) [G01N 29/024 (2013.01); G01N 29/222 (2013.01); G01N 29/2437 (2013.01); G01N 2291/011 (2013.01); G01N 2291/014 (2013.01); G01N 2291/021 (2013.01); G01N 2291/02881 (2013.01); G01N 2291/102 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of measuring gas characteristics at low pressure atmospheres, the steps comprising:
providing an air path chamber having a first speaker located on a substrate on a first end of the air path chamber, a first microphone located within the air path chamber on a second end of the air path chamber opposite the first speaker, a conductive chamber extending outward from the first speaker at a first end of the conductive chamber, opposite the air path chamber and having a second microphone at a second end of the conductive chamber;
inserting a gas into the air path chamber;
initiating a first sound wave within the air path chamber through the first speaker;
receiving the first sound wave at the first microphone located within the air path chamber;
receiving a second sound wave produced by the first speaker at the second microphone located within the conductive chamber;
calculating a frequency of the first sound wave;
calculating the speed of the first sound wave;
calculating a k/M ratio of the gas;
calculating a temperature of the gas based upon the k/M ratio, frequency and speed of the sound wave;
amplifying the first sound wave received at the first microphone and amplifying the second sound wave at the second microphone; and
calculating a summed sound wave by subtracting the first received sound wave at the first microphone from the second received sound wave at the second microphone.