MEASURING CONDUIT FOR FLOW RATE AND CONCENTRATION OF FLUID

摘要

A measuring conduit adapted for flow rate and concentration of a fluid for use in a measuring apparatus which measures both the flow rate of the fluid such as a respiratory gas containing a particular gas component, for example, carbon dioxide, using an ultrasonic wave and the concentration of the particular gas component in an optical manner. In order to simultaneously measure the flow rate and concentration and also to reduce the dead space of the measuring conduit, this measuring conduit comprises a single conduit member through which the fluid flows; a pair of ultrasonic transducers attached to the conduit member so as to face each other along a line slanted with respect to a flow direction of the fluid; and a pair of light transmitting windows airtightly provided in the wall of the conduit member between the ultrasonic transducers so as to face each other. One of the light transmitting windows introduces a light beam from an external light source into the conduit member. The other light transmitting window introduces the light penetrating the fluid flowing through the conduit member into a photo detecting element of the measuring apparatus.