Publish Time: 2026-09-11 Origin: Site
A centrifuge can look normal, finish every run and show no alarm while its actual speed, time or temperature is already drifting. Calibration is not about proving that the machine still spins. It is about proving that the operating conditions applied to the sample are still trustworthy.
Can the laboratory still trust the centrifugal conditions this instrument applies to its samples?
These activities are closely related, but they do not answer the same question. The International Vocabulary of Metrology distinguishes calibration from verification and adjustment. Calibration establishes the relationship between an indication and a reference quantity value with associated measurement uncertainty. Verification asks whether a specified requirement is fulfilled. Adjustment changes the measuring system so that it provides prescribed indications.
Is the centrifuge physically clean and in an appropriate operating condition?
Physical conditionDo lid locking, imbalance protection and other safety functions behave as intended?
FunctionBetween formal calibrations, are speed, time or temperature still inside the predefined limit?
Status between calibrationsWhat is the measured relationship between centrifuge performance and a controlled reference?
Metrological evidenceA well-maintained centrifuge can still drift out of calibration. A calibrated centrifuge can still have a damaged rotor or another mechanical condition that requires attention.
Speed error changes the centrifugal field. A displayed value is not an independent reference measurement.
Timer accuracy and the protocol definition of “10 minutes” are separate questions.
Refrigerated chamber temperature and sample thermal history are related, but they are not identical claims.
If a centrifuge is programmed to 10,000 rpm and the display also reads 10,000 rpm, the control system is reporting that value. For a method defined by relative centrifugal force, the actual speed matters because centrifugal force depends on the square of RPM.
At constant rotor radius, a +1% RPM error produces approximately +2.01% RCF.
A −1% RPM error produces approximately −1.99% RCF.
Accurate speed therefore does not eliminate the need to identify the correct rotor and effective radius. A wrong radius can still produce an incorrect RCF calculation even when RPM is measured correctly.
If a high-speed centrifuge performs its critical work around 15,000–18,000 rpm, a calibration performed only at 1,000 rpm provides limited evidence about the region that matters most. Useful test points should reflect common operating speeds, critical method setpoints, instrument capability and laboratory risk.
| GlanLab Model | Max Speed | Max RCF | Published Speed Accuracy | Temperature Range | Published Temperature Accuracy |
|---|---|---|---|---|---|
| YT5AR | 5,000 rpm | 4,730 ×g | ±20 rpm | −20 to 40°C | ±1°C |
| YF10 | 10,000 rpm | 15,730 ×g | ±20 rpm | −20 to 40°C | ±1°C |
| YT20R | 21,000 rpm | 30,910 ×g | ±20 rpm | −20 to 40°C | ±1°C |
Current GlanLab published model specifications. Always use the current specification and the exact rotor configuration when defining an acceptance or verification plan.
Maximum speed and maximum RCF describe the available operating envelope. Published speed accuracy and temperature accuracy describe how the model's control performance is specified. For laboratory quality control, both dimensions matter.
Timer verification can compare the centrifuge timer against a controlled reference. But the method must also define what those ten minutes represent.
At START, when the rotor begins to move, or only after target speed has been reached?
“10 minutes at target RCF” is not automatically the same as a 10-minute total cycle.
At the start of deceleration or only when the rotor has completely stopped?
Timer accuracy is an equipment-performance question. Protocol timing definition is a method question. Both have to be clear if an experiment is to be reproduced correctly.
A refrigerated centrifuge is a thermal system, not just a cold chamber. Rotor mass, adapters, tubes, sample volume, starting temperature, speed and run time all influence the actual temperature history of the sample.
Instrument temperature-control accuracy and actual sample-temperature performance are related but should not be treated as identical claims.
For GlanLab refrigerated models such as YT5AR, YF10 and YT20R, current published specifications include a temperature range of −20 to 40°C and a temperature accuracy of ±1°C. These are model-level performance specifications. Temperature-sensitive methods may still require the laboratory to verify actual sample performance under representative rotor, load and run conditions.
Rotor cracks, corrosion, deformation and impact history belong primarily to physical inspection and lifecycle management. Lid locking, imbalance protection and overspeed protection are more accurately treated as functional checks.
Separating these activities creates better records: what was quantitatively measured, what was functionally tested, and what was physically inspected.
“Once a year” can be a perfectly reasonable answer for a particular laboratory. It is not a universal metrological rule.
ILAC-G24:2022 / OIML D 10:2022 states that recalibration intervals should be selected and reviewed using evidence such as risk, required measurement performance, manufacturer information, wear or drift tendency, usage severity, environmental conditions, historical calibration data, intermediate checks, transportation risk and applicable requirements.
What happens if speed, time or temperature drifts?
How often, how fast and how heavily is the centrifuge operated?
What do previous calibration results show?
Is performance remaining stable between formal calibrations?
Has maintenance, repair or adjustment changed the risk profile?
Could movement or reinstallation have affected performance?
What performance does the exact model claim?
What does the laboratory or applicable standard require?
A newly commissioned centrifuge has little historical evidence about drift behavior. Initial verification or calibration may therefore be performed more frequently until enough data exist to justify a stable interval. The interval can mature with the evidence.
If a centrifuge passes calibration on day 1 and fails on day 365, the laboratory still has to ask when the drift actually began. Intermediate checks reduce the unknown period between the last known acceptable state and the first observed abnormal state.
If each result is recorded only as pass/fail, the four checks appear identical.
Storing the actual measured values reveals whether performance is stable, drifting or moving toward a predefined limit.
Is this result acceptable? The answer cannot be invented after the measurement.
Acceptance criteria should already exist and may come from the exact model specification, a validated method, the laboratory quality system or an applicable normative requirement.
Calibration provides the measured relationship. Verification determines whether that relationship satisfies the predefined requirement.
A handheld tachometer does not become a reliable reference simply because it displays more digits than the centrifuge. The laboratory should know its calibration status, measurement range, uncertainty, measurement method and test conditions.
The International Vocabulary of Metrology treats calibration as part of a measurement chain that includes reference quantity values and associated uncertainty. Comparing two uncontrolled displays is not the same thing.
Reassess speed-related performance before critical use resumes.
Reassess the temperature-control characteristics affected by the intervention.
Evaluate which performance characteristics could reasonably have changed.
A trend approaching the acceptance limit deserves attention before the next scheduled calibration.
Reassess calibration status immediately rather than waiting for the annual date.
Address rotor condition and safety separately from instrument calibration.
Adjustment and successful recalibration can establish that the centrifuge is acceptable now. They do not automatically establish when the instrument first left the acceptable range.
Last known acceptable state → first observed drift → work performed in between → possible result impact → corrective action.
Maximum speed, maximum RCF and maximum capacity are important, but laboratories with defined quality requirements should also ask whether control-performance specifications and documentation are available.
GlanLab publishes speed accuracy, temperature accuracy where applicable, rotor-specific RCF information and other model-level technical data for multiple centrifuge platforms. This gives laboratories a clearer basis for incoming acceptance, routine verification and long-term equipment control.
Detect rotor, bucket and accessory risks.
Control contamination and corrosion risks.
Confirm protection and control functions.
Detect drift between formal calibrations.
Establish metrological confidence in critical parameters.
Confirm acceptable status after relevant repair or adjustment.
A twelve-month interval can be entirely appropriate when it is supported by the laboratory quality system, applicable requirements, equipment information, stable historical results, satisfactory intermediate checks and an acceptable level of method risk.
The issue is not the number twelve. The issue is whether evidence supports it.
| Record Field | Why It Matters |
|---|---|
| Parameter Tested | Clarifies whether speed, time, temperature or another characteristic was evaluated. |
| Test Points | Shows whether the relevant operating range was actually represented. |
| Actual Measured Values | Enables drift analysis instead of storing only pass/fail. |
| Reference Instrument | Identifies the metrological reference used for comparison. |
| Reference Status & Uncertainty | Supports confidence in the measurement chain. |
| Acceptance Criteria | Defines what pass/fail means before the result is known. |
| Adjustment / Repair History | Shows whether the instrument state changed before recalibration. |
| Trend vs Previous Results | Provides evidence for future interval and risk decisions. |
A mature centrifuge-control program protects four things: safety, measurement performance, method reproducibility and equipment availability.
The laboratory ultimately needs confidence that the intended centrifugal force is being produced, the programmed time corresponds to the method, temperature performance is suitable for the sample, and drift can be detected before important work is compromised.
Which centrifuge performance characteristics matter to this method, what error can the method tolerate, how will drift be detected between formal calibrations, and does the instrument's own history still justify the current interval?