This hotwire calibration unit is the latest iteration in a long line of calibration units. This unit has the capability to calibrate a double x-wire probe from +/- 36 degrees in two perpendicular planes. The unit uses automated movement via the use of two stepper motors located on top and on the side of the aluminum traverse. Internally this calibration unit uses two layers of flow conditioning mesh, followed by a one inch layers of flow straighteners, or "soda straws".