Psychrometers are used to measure a dry bulb temperature along with a hummidity measurement in order to gauge the air conditions of a space. Psychrometers work best when there is a steady flow of air over the sensor and this is difficult to find in an open space. For example, checking the air conditions of a conditioned space in comparison with the readings of an air conditioning unit. This psychrometer air tunnel was designed to generate an airflow over a sensor of a hand-held, in-duct, psychrometer. One end of the tunnel is open where a separate end cap was designed to attach a fan. The installed fan is used to generate an airflow in a pull-manner where the air stream is being pulled through the tunnel and exiting through the fan. This allows for less turbulent flow in the tunnel. In working with making the airflow less turbulent, on the opposite end of the tunnel, an air straightener is attached. There is not a current commercial product that does this.