The test kit uses a fan to suspend a ball in a column of air within a transparent tube. The speed of the fan is regulated using a voltage supplied by control electronics housed in the base of the device. The height of the ball is detected using an ultrasonic sensor located at the top of the tube. This information along with control settings are displayed using software on a standard pc. The user interface can be switched between control of ball position and direct control of the fan for identification purposes.