For all you posters discussing turntable speed accuracy It is not possible to measure wow & flutter using a test record.
If you use a rotary function generator to measure the turntable performance directly off the platter, the results will be more accurate than any test record.
For an explanation from someone who actually has a degree in physics and acoustical engineering - Bruce Thigpen of Eminent Technology.
Here is Bruces explanation from his Eminent Technology website.
Bruce has many patents and inventions including his unique air bearing tonearm, rotary subwoofer, vacuum platter as implenmented by SOTA, and many others.
Bruce Thigpen -
Reviewers have incorrectly attributed wow and flutter to the turntable. Since the advent of the belt drive turntable, wow and flutter has been purely a function of tonearm geometry, the phono cartridge compliance with the elastomeric damping, and surface irregularities in the LP. In our own lab we have measured many high quality turntables using a rotary function generator directly connected to the platters of the turntables.
The measured results are usually an order of magnitude better than the results using a tonearm and test record (conventional wow and flutter method). Further proof exists if you take two tonearms, one straight line and one pivoted and mount them both on the same turntable. The straight line tonearm will give a wow and flutter reading with the same cartridge/test record of about 2/3 to 1⁄2that of the pivoted arm (.03% < .07% to .05%). This is because the straight line tonearm has a geometry advantage and lateral motion does not result in stylus longitudinal motion along the groove of the record.
Another proof is to take two different cartridges, one high compliance and one low compliance, and take measurements with both using the same turntable and tonearm. The reading of wow and flutter will be different. All wow and flutter readings are higher than the rotational consistency of the turntable.