Towing a drag chute could get a bit complicated, since the drag of a parachute varies quite a bit with shape, but the parachute drag could be calibrated in a relatively small wind tunnel, or perhaps by towing behind a car on a towline long enough to get it out of most of the wind wash generated by the car.

Most university engineering departments have wind tunnels, but they usually have rather small test sections. Only a few of the larger universities commonly have wind tunnels with test sections larger than about two feet square, and they are very costly to operate. I did some engineering work to fix an underperforming wind tunnel recently which had a test section of about three feet square, and consumed about 300 HP to produce about 150 mph wind, generating quite an electric bill in the process.