Free Engineering Tool
Vibration Severity Chart
Interactive ISO 10816 / 20816 vibration severity chart. Enter measured velocity and machine class to evaluate zone A/B/C/D instantly.
The chart mirrors the zone evaluation built into the Vibromera Balanset-1A, which assesses measured RMS velocity against ISO 10816 and ISO 20816 limits during field balancing.
Evaluation
| Velocity (mm/s RMS) |
Class I ≤15 kW |
Class II 15–75 kW |
Class III >300 kW rigid |
Class IV >300 kW flex |
|---|
ISO 10816 / 20816 Overview
ISO 10816 (now superseded by ISO 20816) classifies vibration severity based on broadband velocity in mm/s RMS, measured on the bearing housing of rotating machines. The standard defines four evaluation zones:
- Zone A — Vibration of newly commissioned or reconditioned machines
- Zone B — Acceptable for unrestricted long-term operation
- Zone C — Not suitable for long-term continuous operation; remedial action required
- Zone D — Dangerous vibration levels; damage could occur; immediate action needed
Machine Classes
| Class | Description | Examples |
|---|---|---|
| I | Small machines ≤15 kW | Small pumps, fans, electric motors |
| II | Medium machines 15–75 kW (or ≤300 kW on special foundations) | Medium motors, pumps, generators |
| III | Large machines >300 kW on rigid/heavy foundations | Large motors, centrifugal compressors |
| IV | Large machines >300 kW on flexible/lightweight foundations | Turbogenerators, gas turbines, large fans |
Zone Boundary Values (mm/s RMS)
| Boundary | Class I | Class II | Class III | Class IV |
|---|---|---|---|---|
| A/B | 0.71 | 1.12 | 1.80 | 2.80 |
| B/C | 1.80 | 2.80 | 4.50 | 7.10 |
| C/D | 4.50 | 7.10 | 11.2 | 18.0 |
ℹ️ Note: These class-based values are from ISO 10816-1 Annex B (formerly ISO 2372) for general industrial machinery; note that ISO 10816-3 / 20816-3 use a different Group 1–4 scheme. Specific machine types (e.g., reciprocating machines, hydraulic machines) have their own sub-parts with different limits. ISO 20816-1 provides the general framework.
⚠️ Important: Velocity is measured as broadband RMS in the 10–1000 Hz range. Peak velocity or narrowband readings should not be directly compared with these limits.
Professional vibration meters with ISO 10816 evaluation built in. Measure, diagnose, and report in the field.
Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
