MiniProf Wheel 400 is equipped with a wide 400 mm backplate and is our best option for profile and diameter readings in one single measurement.
Due to the large backplate, diameter readings are improved significantly and are three times less sensitive to the state of the wheel and measuring process compared to MiniProf Wheel 250.
As with most similar tools, the diameter is based on the common used Versine measuring principle and an assumption of an ideal wheel without local deformations. This should always be considered when handling diameter.