Which two parameters are calibrated in centrifuge performance, and how frequently should calibration be performed?

• A. Timer (stopwatch) and speed (tachometer and strobe); every 3 months
• B. Temperature and rotor balance; yearly
• C. Humidity and volume; monthly
• D. Viscosity and pH; weekly

Answer: (A)

Accurate centrifuge performance hinges on precise timing and rotor speed, because the duration of spin and the exact rpm determine the forces acting on the sample and thus the quality of separation. The two parameters that are calibrated are the timing function (how long a run lasts) and the speed measurement or setting (rpm), typically checked with a tachometer or a strobe. Calibrating these ensures the machine actually runs for the intended interval and at the intended speed, which is essential for reproducible results and safety. The calibration is usually performed every three months to catch gradual drift from wear or sensor changes and to align with routine quality-control schedules. Other factors like temperature, rotor balance, or sample properties (humidity, viscosity, pH) affect performance or safety but are not the standard calibration targets for the centrifuge’s operational accuracy.