US 12,326,421 B2
System, method, and apparatus for detecting air in a fluid line using active rectification
Michael J. Wilt, Windham, NH (US); and Jason M. Sachs, Chandler, AZ (US)
Assigned to DEKA Products Limited Partnership, Manchester, NH (US)
Filed by DEKA Products Limited Partnership, Manchester, NH (US)
Filed on Aug. 21, 2023, as Appl. No. 18/235,914.
Application 17/004,125 is a division of application No. 15/341,611, filed on Nov. 2, 2016, granted, now 10,761,061, issued on Sep. 1, 2020.
Application 18/235,914 is a continuation of application No. 17/004,125, filed on Aug. 27, 2020, granted, now 11,733,208.
Application 15/341,611 is a continuation of application No. 14/101,848, filed on Dec. 10, 2013, granted, now 9,518,958, issued on Dec. 13, 2016.
Claims priority of provisional application 61/738,447, filed on Dec. 18, 2012.
Prior Publication US 2023/0393096 A1, Dec. 7, 2023
Int. Cl. G01N 29/02 (2006.01); G01N 29/032 (2006.01); G01N 29/44 (2006.01)
CPC G01N 29/02 (2013.01) [G01N 29/032 (2013.01); G01N 29/4427 (2013.01); G01N 2291/02433 (2013.01); G01N 2291/102 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of detecting air, the method comprising:
transmitting ultrasonic energy;
receiving the ultrasonic energy;
transducing the received ultrasonic energy into a receiver signal;
actively rectifying the receiver signal to provide a processed signal by inverting the receiver to provide an inverted receiver signal;
determining whether the processed signal is less than a predetermined threshold;
inverting the receiver signal to provide an inverted receiver signal;
switching between the receiver signal and the inverted receiver signal in accordance with a first switching signal to provide a first switch output; and
integrating the first switch output to provide a first integrated output for a predetermined number of cycles.