You will also use a temperature transducer to indirectly measure airflow from one nostril. Each inhale brings cooler air across
the transducer, and each exhale blows warmer air across the transducer. The temperature of the air passing by the temperature
probe is inversely related to the expansion or contraction of the Subject’s chest. This indirect method is efficient when rate
and relative amplitude measurements are all that’s required; a direct airflow measurement requires more complicated
equipment and data processing.