Documented shaft speed and requested orders
Shaft-Speed Order Frequency Calculator
Convert a documented shaft speed and any positive integer or fractional orders to frequency, cycles per minute, period and angular frequency.
Order-frequency arithmetic
| Order k | Frequency Hz | KST | Period ms | Angular frequency rad/s |
|---|
Implemented unit arithmetic
fk = kf1×
KSTk = kn
Tk = 1/fk
ωk = 2πfk
n is the documented shaft speed in revolutions per minute, k is the dimensionless order, f is hertz, T is seconds (displayed in milliseconds) and ω is radians per second. These are exact unit/period relations apart from finite numerical representation; they are general mathematics, not an ISO diagnostic formula.
Harmonic versus order
Integer orders 1×, 2×, 3×… are harmonics of the 1× rotational frequency. Order analysis can also use fractional or non-integer orders; those are not integer harmonics. An order label is speed-normalized, while its absolute frequency changes with shaft speed.
Why automatic fault labels were removed
The former FAQ assigned unbalance, misalignment, looseness, cracked shafts, blade problems and gear faults to individual orders as if frequency alone established cause. Real spectra can share frequencies across mechanisms, and resonance, modulation, geometry and operating state affect amplitudes and phase. This calculator therefore produces only traceable frequency arithmetic.
Not a diagnosis: blade-pass or gear-mesh order must be derived from the correct component count and the speed of the associated shaft. Phase is meaningful only with a defined reference and measurement chain; it does not directly reveal a heavy-spot angle without the machine response and balancing procedure.
