PRPmed · Knowledge & Tools
Technical reference database · Version 1.2.1

Centrifuge & Rotor Radius Database

The device name alone does not determine the rotor radius. The rotor, sleeve or adapter and the vessel used can change the effective radius. The database documents these configurations, checks published RCF/RPM values mathematically and flags source conflicts.

Search database Open RCF/RPM calculator
—Centrifuges / model groups
—rotors
—Vessel/adapter entries
—marked as PRP format
Technical guidance, not device approval. Manufacturer documentation, IFU, rotor approval, permitted vessels and the specific processing protocol remain decisive. Class B values are calculated from published maximum values and are clearly labelled.
Why this database?

Two typical sources of error — both dependent on manufacturer data

Rotor radius is not a general device property. Even manufacturer documents can contain contradictory table values. The database makes both issues visible before an RPM value is transferred.

Praxisfall 01 · Hettich EBA 270

Same centrifuge — different radii for different sleeves

With the built-in swing-out rotor, sleeve and vessel position change the documented radius. The same target RCF therefore requires different speeds.

Speed difference between 126 and 101 mm—
sleeve 2331-6 · bore 17,5 × 80

long sleeve / larger radius position

126 mm
for 1.200 × g: —
sleeve 2333-6 · bore 17,5 × 55

short sleeve / smaller radius position

101 mm
for 1.200 × g: —
RPM for 126 mm mistakenly used at 101 mm → actual value only—
RPM for 101 mm mistakenly used at 126 mm → actual value about—
deviceRotorsleeve / Adaptervessel / Position

The displayed 126 mm and 101 mm come from Hettich table values recorded in the database. RPM is calculated solely from the selected target RCF.

Praxisfall 02 · Hettich EBA 200 / EBA 200 S

When the data sheet is mathematically inconsistent

The database does not copy published values blindly. When radius, maximum speed and RCF are stated together, they are checked against the same standard formula. Deviations remain visible and are not silently corrected.

Entryprinted radiusManufacturer RCF / RPMmathematically impliedStatus
13 × 75 mm · EBA 20069 mm2.697 × g bei 6.000 min⁻¹—Conflict
13 × 75 mm · EBA 200 S69 mm4.794 × g bei 8.000 min⁻¹—Conflict
13 × 75 mm · Vergleichszeile67 mm2.697 / 4.794 × g≈ 67 mmmathematically plausible
12 × 60 mm · EBA 20066 mm2.656 × g bei 6.000 min⁻¹—plausible
12 × 60 mm · EBA 200 S66 mm5.009 × g bei 8.000 min⁻¹—flagged
Important: The database does not automatically replace a flagged manufacturer value with the mathematically likely value. It shows the original value, formula check and conflict status side by side. A final correction should be confirmed by the manufacturer.
Device → rotor → sleeve/adapter → vessel

Select configuration

Search by manufacturer, model, rotor, sleeve, adapter or vessel. The radius is assigned to the specific configuration, not generally to the device name.

Select device

Select a model on the left. Rotor, vessel, radius, RCF/RPM calculation and technical visualization will then be available.

Interaktiv

Why radius changes RCF

The charts respond to the currently selected rotor/vessel combination, showing why the same RPM value cannot be transferred to every centrifuge.

Rotor & measurement path

Schematic view of the selected rotor type. The decisive value is the distance from the axis of rotation to the defined point in the vessel.

RCF curve for selection

RCF increases with the square of speed. The target RCF from the calculator is shown as a reference line.

Same speed, different radii

Comparison of radii available in the selected device at one common speed.

3.500 RPM
Quality assurance

Source status and automatic plausibility check

The database distinguishes direct manufacturer values from calculated radii. RCF, RPM and radius are also checked against each other.

Formula check of the current database

For every checkable record, manufacturer RCF, speed and radius are tested for consistency within the defined tolerance.

—Value pairs within tolerance
—flagged value pairs
—only with rounding tolerance

Source classes

A green A is stronger evidence than a yellow B. Class C is not included in the public calculation.

A
Direct manufacturer valueThe radius is stated directly in the manufacturer data sheet or rotor/adapter manual.
B
Calculated from published valuesRadius derived from published maximum speed and maximum RCF; valid only for the stated rotor.
Methodology

How to read the database

Radius does not belong generally to the device name. The actual chain of device, rotor, sleeve/adapter and vessel or position is decisive.

01

Device ≠ radius

A model name alone is insufficient. With interchangeable rotors and different accessories, the same device can have several documented radii.

02

Check sleeve/adapter separately

The EBA 270 illustrates this clearly: 2331-6 and 2333-6 produce 126 and 101 mm respectively in the same device. This level must be known before calculating RPM.

03

Check source values mathematically

When radius, RPM and RCF are published together, they are checked against each other. Contradictions are flagged; the tool does not silently alter manufacturer documents.

RCF = 1,118 × 10⁻⁵ × r[cm] × RPM²

For reverse calculation: RPM = √(RCF / (1.118 × 10⁻⁵ × r[cm])).

Privacy on this tool page

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The standalone application is designed to minimize data use. Calculations, filters and charts run locally in the browser.

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✓ Local calculation

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Data provenance

Manufacturer and rotor sources

Each entry includes the data source used. Where only reverse calculation was possible, this is stated explicitly.

FAQ

Frequently asked questions about the rotor radius database

Why does the EBA 270 show several radii?

Because sleeve and vessel position change the distance from the axis of rotation. Hettich data list 126 mm for sleeve 2331-6 with a 17.5 × 80 bore and 101 mm for sleeve 2333-6 with a 17.5 × 55 bore. The sleeve is therefore a separate selection step.

Why are contradictory manufacturer values not simply corrected?

Because a reference database should separate the original source from its own plausibility check. A mathematical contradiction may indicate a table or printing error but does not replace manufacturer confirmation. The printed value remains visible and automatic calculation is blocked for flagged records.

Why can the same centrifuge have several rotor radii?

Because the effective distance from the axis of rotation to the vessel is affected by rotor, adapter, sleeve, vessel length and operating position. A single radius per device name may therefore be wrong.

Can runtime be determined automatically from rotor radius?

No. The required RPM can be calculated from radius and target RCF. Runtime belongs to the relevant manufacturer or processing protocol and is not derived from the RCF formula.

What does source class B mean?

The radius was not stated directly in the available manufacturer document. It was calculated from published maximum speed and maximum RCF and applies only to the specifically named rotor.

What does “PRP format” mean?

The marker only identifies vessel sizes or configurations whose format may be relevant to typical PRP tubes. It does not state product compatibility and is not medical or regulatory approval.