6-lug wheels are measured like 4-lug wheels. Bolt pattern or bolt circle is the diameter of an imaginary circle formed by the centers of the wheel lugs.. Note: When measuring a 5-lug wheel the measurement is only an estimate unless accurately measured using a bolt pattern gauge. A bolt pattern gauge is a specialty tool and is not widely available.
Palpation should be done using the fingertips and intensity of the pulse graded on a scale of 0 to 4 +:0 indicating no palpable pulse; 1 + indicating a faint, but detectable pulse; 2 + suggesting a slightly more diminished pulse than normal; 3 + is a normal pulse; and 4 + indicating a bounding pulse.
As the disk rotates faster, the pulse frequency increases accordingly. Since the relationship between pulse frequency and rotational velocity is linear, it is a simple matter to use the pulse frequency as an indication of speed. The output pulses can be transformed into speed units by measuring their frequency, and then multiplying the frequency by an appropriate scale factor.