A centrifuge looks like it's doing its job as long as it spins. But the set speed and the actual speed can quietly drift apart — and when they do, your results pay the price. Here's why RPM verification matters more than most labs realize, and how it works.
Why a few hundred RPM matters
Centrifugal force depends on speed. A rotor running below (or above) its set RPM changes the g-force applied to your samples, which can affect packed-cell volumes, density separations, plasma/serum quality, and molecular preps. The result isn't a dramatic failure — it's a subtle, systematic error that's hard to catch because everything looks normal.
How RPM verification works
A technician measures actual rotor speed with a calibrated, NIST-traceable tachometer and compares it to the set speed across the operating range, then verifies the timer. The as-found and as-left readings are recorded against your defined tolerance — commonly around ±5%, depending on application and manufacturer spec.
Signs your centrifuge needs a check
- It's been over a year since the last verification.
- Inconsistent separations or unexpected result drift.
- Unusual noise, vibration, or longer spin-up.
- No current calibration certificate or label on the unit.
A centrifuge that's off-speed doesn't break — it just quietly biases every spin.
Keeping it documented
Beyond result quality, CLIA-regulated labs are expected to verify centrifuge performance on a schedule, with documentation. Annual verification with a traceable certificate covers both the science and the survey. Learn more about centrifuge calibration & RPM verification , or request a readiness check to see which of your instruments are due.
Not sure where your equipment stands?
Request a free Compliance & Equipment Readiness Assessment — we’ll spot-check your gear and documentation and leave you a short report.