Patent ID: 8899108

Claim:
A flow sensor, comprising: a main flow body having a first main flow port, a second main flow port, and a main flow channel between the first main flow port and the second main flow port; a laminar flow element disposed within the main flow channel between the first main flow port and the second main flow port and having a first end, a second end, and an outer surface, the first end facing the first main flow port, the second end facing the second main flow port; a first bypass channel formed in, and extending at least partially around, the outer surface of the laminar flow element, the first bypass channel in fluid communication with the main flow channel and defining a first bypass flow passage between the laminar flow element and the main flow body; a second bypass channel formed in, and extending at least partially around, the outer surface of the laminar flow element, the second bypass channel in fluid communication with the main flow channel and defining a second bypass flow passage between the laminar flow element and the main flow body; and a plurality of keying features formed on the outer surface of the laminar flow element, whereby the laminar flow element may be rotated to, and disposed in, a plurality of rotational positions within the main flow body, wherein: the first and second bypass channels each have an effective length; and varying the rotational position of the laminar flow element varies the effective length of the first and second bypass channels.