Tachometer checks

Ozark Biomedical may be able to assist. 

"Frequency Converter
The frequency converter provides the drive motor with squarewaved voltage blocks
having an amplitude of the half of the DC intermediate circuit voltage. These blocks
are variable controlled in frequency and pulse-width modulation. Beginning with low
frequency and small pulse-width blocks, both parameters will be increased up to the
operators set speed. The set speed value will be reached with a tolerance of ± 5%
(within the valid mains voltage range)"

This instrument appears to have been sold by various facets of Abbott, Heraeus, Kendro, Sorvall, and Thermo, but all the same basic instrument.

From the Abbott user manual for Biofuge 13. This is the best description I've seen:

Fill 24 tubes with 1.5ml of water, and cap them

Load them into the rotor.

Use an optical tach

start and run for 30 seconds (before testing speed)

speed should be 13,000 +/- 5%

I uploaded the Abbott user and service manuals for the Biofuge 13. It seems to be basically the same instrument as the Heraeus. The rotor might be different, Abbott versus Heraeus, but the speed tolerance specs ought to be the same.

Thank you Ross - the manuals have been uploaded HERE. 

Thank you guys so much!