เครื่องคำนวณความเร่งจากการสั่นสะเทือน (ISO 20816)

Vibration acceleration is the rate of change of vibration velocity, measured in m/s² or g (where 1 g = 9.80665 m/s²). It is the most sensitive parameter to high-frequency vibration and is critical for detecting bearing defects, gear mesh faults, and other high-frequency mechanical problems.

Acceleration increases with both vibration amplitude and frequency, making it the parameter of choice for frequencies above 1000 Hz.

Acceleration is preferred for high-frequency vibration analysis, typically above 1000 Hz. It is the best parameter for early detection of rolling element bearing defects, gear mesh problems, and cavitation.

Velocity (mm/s RMS) remains better for general machine condition assessment in the 10–1000 Hz range per ISO 10816 / ISO 20816. Many modern monitoring systems use acceleration enveloping (demodulation) for bearing diagnostics.

To convert from g to m/s², multiply by 9.80665 (the standard acceleration due to gravity). For example, 0.5 g = 0.5 × 9.80665 = 4.903 m/s².

Conversely, to convert from m/s² to g, divide by 9.80665. The g unit is popular in vibration analysis because typical industrial vibration levels fall in a convenient numeric range — roughly 0.01 to 50 g.

Piezoelectric accelerometers are the standard sensors for vibration acceleration measurement. IEPE (ICP) type accelerometers with integrated electronics are most common in industrial applications, offering wide frequency range (0.5 Hz to 20+ kHz), high sensitivity, and excellent durability.

MEMS accelerometers provide lower-cost alternatives for monitoring systems. Charge-mode piezoelectric accelerometers are used in high-temperature environments above 120 °C.

Typical vibration acceleration levels depend on machine type, speed, and frequency. For general industrial machinery at operating speed:

• < 0.5 g — Good condition
• 0.5–2 g — Acceptable
• 2–5 g — Alarm level
• > 5 g — Investigate immediately

High-frequency bearing defect signals can reach 10–50 g peak. ISO 20816 primarily defines zone boundaries using velocity, but acceleration is essential for high-frequency diagnostics.