ISO 10816 Vibration Severity Standard

ISO 10816 provides guidelines for evaluating machine vibration by measuring vibration velocity on non-rotating parts (bearing housings, pedestals, foundations). The standard classifies machinery and defines severity zones based on vibration levels.

The current versions include ISO 10816-1 (general guidelines), ISO 10816-3 (industrial machines 15kW to 300kW), and specialized parts for different machine types. ISO 20816 is gradually replacing ISO 10816 with updated criteria.

Vibration Parameters: Velocity vs Displacement vs Acceleration

Machinery vibration can be measured as displacement, velocity, or acceleration. Each parameter has optimal frequency ranges:

• Displacement (mils, um): Best for low frequencies (below 10 Hz). Used for slow-speed machinery, structural movement, and shaft position monitoring.
• Velocity (mm/s, in/s): The primary parameter for general machinery monitoring (10-1000 Hz). ISO 10816 uses velocity RMS as the severity criterion. Velocity correlates well with vibration energy and fatigue stress.
• Acceleration (g, mm/s2): Best for high frequencies (above 1000 Hz). Used for bearing fault detection, gear mesh analysis, and high-speed machinery.

The relationship between parameters at a given frequency (f in Hz):

Velocity = 2 x pi x f x Displacement

Acceleration = 2 x pi x f x Velocity

Machine Classification per ISO 10816-3

Machines are classified based on power rating and foundation type:

• Class I: Small machines up to 15 kW. Examples: small pumps, fans, motors directly coupled to machinery.
• Class II: Medium machines 15-75 kW without special foundations, or up to 300 kW on special foundations. Most common industrial machinery.
• Class III: Large machines above 75 kW on rigid and heavy foundations. Large pumps, compressors, and motors on concrete bases.
• Class IV: Large machines above 75 kW on flexible or lightweight foundations. Machines on steel structures or isolated mounts.

Severity Zones A, B, C, D

ISO 10816 defines four evaluation zones based on vibration velocity:

• Zone A (Green): Vibration of newly commissioned machines. Excellent condition.
• Zone B (Blue/Cyan): Acceptable for unrestricted long-term operation.
• Zone C (Yellow): Unsatisfactory for long-term operation. Remedial action should be taken at next opportunity.
• Zone D (Red): Sufficiently severe to cause damage. Immediate action required - stop machine or reduce load.

Measurement Best Practices

• Measure at bearing housings in horizontal, vertical, and axial directions
• Use RMS (Root Mean Square) velocity for ISO 10816 compliance
• Frequency range typically 10-1000 Hz for general machinery
• Take measurements at consistent operating conditions (speed, load, temperature)
• Trend readings over time to detect degradation before failure

Vibration Waveform Types