How to assemble a gas concentration flow rate measuring device, an oxygen concentrator, and a gas concentration flow rate measuring device

摘要

PROBLEM TO BE SOLVED: To provide a gas concentration flow rate measuring device or the like capable of simplifying assembly and reducing costs. SOLUTION: A measuring unit 20 forming a measuring flow path F through which gas flows, a pair of ultrasonic sensors arranged on the upstream side and the downstream side of the measuring flow path F, respectively, and a temperature sensor for measuring the temperature of gas. A measuring unit including an arithmetic control device for calculating the flow rate of the gas and the concentration of a specific component in the gas, and a device board 50 having a device board pattern for electrically connecting at least an ultrasonic sensor. A claw portion 28 is provided on one of the 20 and the device board 50, and the claw portion 28 is engaged with the other of the measuring section 20 and the device board 50 so that the measuring section 20 and the device board 50 are engaged with each other. An engaging surface 50c that restricts relative movement of the substrate 50 in the thickness direction is provided. [Selection diagram] FIG. 6