Documented input · physical arithmetic only

Documented Residual-Unbalance Force Worksheet

Convert one externally approved residual-unbalance magnitude into specific unbalance, angular speed, idealized rotating-force magnitude and relative centrifugal acceleration.

no G-grade selectionno plane allocationno bearing-load predictionno ISO compliance verdict

This worksheet does not specify a balancing tolerance. It does not decide whether a separator, centrifuge or other rotor behaves rigidly or flexibly, choose a balance quality grade, determine correction planes, allocate residual unbalance, assess balancing errors or replace OEM safety and acceptance procedures.

Controlled residual-unbalance record

Enter a residual-unbalance magnitude U already established by the applicable licensed standard, OEM specification, drawing or approved calculation.

Rotor/assembly mass m (kg)Mass corresponding to the same U basis.

Documented residual-unbalance magnitude U (g·mm)Not chosen or limited by this page.

Speed input basisChanging basis clears the speed and result.

Speed/frequency value

Radius input unitChanging unit clears the radius and result.

Documented evaluation radius RGeometric radius for the RCF calculation; not an automatic bowl or liquid radius.

Equipment, rotor/assembly and configuration ID

Governing source, exact edition/revision, clause/table/drawing and jurisdiction

Meaning of U and tolerance-plane/allocation record

Rigid/flexible behaviour evidence and applicable speed range

Balancing/measurement error assessment and uncertainty record

Assembly, product/load, deposits and service-condition record

Evaluation-radius source and RCF purpose

Calculation record ID and reviewer boundary

Required compatibility confirmation U was selected outside this page from the exact applicable controlled source and refers to the recorded mass, assembly, condition, speed range and residual-unbalance basis. The rigid/flexible behaviour decision, correction-plane count and allocation, balancing errors and acceptance method are handled in the controlling procedure. U is suitable for the single-resultant force arithmetic shown here; I will not treat F as a bearing reaction, couple-unbalance effect or structural response. I will not use the outputs as a balance-grade recommendation, operational permission, safety release or ISO/OEM compliance verdict.

Aritmetisk resultat

Entered residual-unbalance magnitude U

Echo of the controlled input, not a permissible value calculated here.

Specific unbalance e=U/m

1 g·mm/kg = 1 μm.

Vinkelhastighet ω

Idealized single-resultant force magnitude F=Uω²

U is converted from g·mm to kg·m by 10⁻⁶.

Relative centrifugal acceleration at R

Ratio to conventional standard gravity gₙ=9.80665 m/s².

Normalized speed and radius

No acceptance or load verdict is produced. Actual bearing forces, casing response, vibration, fatigue and safety depend on unbalance distribution and phase, couple/dynamic components, rotor dynamics, supports, resonances, fluid/product interaction, assembly state and operating transients.

Equations, standards and limits

n=entered RPM, or n=60f when f is entered in Hz; ω=2πn/60

e(μm)=U(g·mm)/m(kg)

F(N)=U(g·mm)×10⁻⁶×ω²

RCF=ω²×R(m)/gₙ; gₙ=9.80665 m/s²; R(m)=R(mm)/1000

These are unit identities and general rotational-kinematics/dynamics equations. They are not presented as formulas supplied by ISO 21940. RCF is an acceleration ratio at the entered geometric radius; it is not by itself separator capacity, separation efficiency or an operating limit.

Why the former G-grade calculator was removed

The previous page automatically offered G1.0 for “high-precision centrifuges”, G2.5 for disc-stack separators and G6.3 for decanters, then labelled the computed U as permissible and ISO 21940-11 compliant. It did not establish rotor behaviour, the applicable exact edition plus amendment, service/balancing speed range, correction planes, allocation, balancing errors, assembly condition, OEM requirements or jurisdiction. Those choices cannot be reconstructed safely from a generic equipment label.

Official lifecycle and public scope inspected

Kilde	Public status and scope used
ISO 21940-11:2016 + Amd 1:2022	Edition 1 remains published and current, with one published amendment. It establishes procedures and tolerances for rotors with rigid behaviour, including magnitude, correction planes, allocation and balancing-process errors; it excludes flexible-behaviour rotors.
ISO 21940-12:2016	Edition 1, published and confirmed in 2025, addresses flexible-behaviour rotors. Its public scope says it is not intended to serve as an acceptance specification for any rotor and may not directly apply to specialized equipment or circumstances.
ISO 21940-14:2012 + Amd 1:2022	Published standard for identifying, assessing and accounting for errors in the unbalance-measuring process and residual-unbalance acceptance checks. Edition 2 is under development; the current licensed text and amendment remain controlling until replacement.
NIST Guide to the SI, Appendix B.9	Conventional standard acceleration of free fall gₙ=9.80665 m/s² used only as the RCF denominator.

Accessed: 15 July 2026. Licensed-source boundary: NEEDS_LICENSED_SOURCE for every balance-quality-grade choice, permissible specific/residual-unbalance value, correction-plane rule, allocation, error allowance and acceptance criterion. None is guessed on this page.

Exact numerical checks

Innganger	e	ω	F	RCF
m=40 kg; U=160 g·mm; n=6000 RPM; R=150 mm	4 μm	628.318530717959 rad/s	63.165468166972 N	6038.51737408148
same physical case: f=100 Hz; R=5.90551181102362 in	4 μm	628.318530717959 rad/s	63.165468166972 N	6038.51737408148

Competent review and OEM procedure required. High-energy rotating assemblies can cause severe injury or equipment damage. Do not run, alter or field-balance a separator/centrifuge solely from this worksheet.