Test your centrifuge for accuracy using the LW Scientific handheld digital tachometer. Be certain that you are spinning fluids at the correct CLIA recommended speeds. How do you know your variable speed centrifuge is spinning urines at 400g? Spinning too slowly may give inadequate results... spinning too fast may damage cell structures. This unit is easy to use with results in only one second. The tachometer will work on any centrifuge with a clear port in the lid allowing the strobe light to reflect off of the rotor.