US 11,927,555 B2
Micromachined thermal time-of-flight fluidic concentration metering device
Liji Huang, Santa Clara, CA (US); Yahong Yao, San Jose, CA (US); Li Chen, San Jose, CA (US); and Chih-Chang Chen, Cupertino, CA (US)
Assigned to Siargo Ltd., Santa Clara, CA (US)
Filed by Liji Huang, Santa Clara, CA (US); Yahong Yao, San Jose, CA (US); Li Chen, San Jose, CA (US); and Chih-Chang Chen, Cupertino, CA (US)
Filed on May 25, 2021, as Appl. No. 17/330,269.
Prior Publication US 2022/0381716 A1, Dec. 1, 2022
Int. Cl. G01N 25/18 (2006.01); G01F 1/68 (2006.01); G01F 1/684 (2006.01); G01F 1/69 (2006.01); G01F 1/692 (2006.01); G01F 1/699 (2006.01); G01F 15/14 (2006.01)
CPC G01N 25/18 (2013.01) [G01F 1/6845 (2013.01); G01F 1/6847 (2013.01); G01F 1/69 (2013.01); G01F 1/692 (2013.01); G01F 1/699 (2013.01); G01F 15/14 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A fluidic concentration metering device utilizing a micro-fabricated sensor based on thermal time-of-flight sensing principle with a capability to metering a full dynamic concentration range comprising:
A fluidic concentration measurement chamber having a fluidic channel that is in a form of a closed conduit and guiding a fluid to be measured;
A micro-machined thermal time-of-flight sensing chip that is used to metering thermal diffusivity of the fluid;
A cavity inside the fluidic concentration measurement chamber, wherein the cavity is connected to the fluidic channel and providing a housing space for the micro-machined thermal time-of-flight sensor chip;
An additional thermistor integrated on the micro-machined thermal time-of-flight sensing chip for a local fluidic temperature measurement;
A recess space between the sensor chip surface and a wall of the fluidic channel, which makes the fluid under a thermal diffusivity measurement at a static state;
A printed circuitry board for the signal conditioning, data processing, and user interface electronics; and
A meter enclosure which is used to housing all components into a complete and stand-alone fluidic concentration metering device, wherein the housing enclosure meets safety requirements for the industrial application domain.