Quick Answer
Vibration meter calibration uses a precision vibration calibrator (back-to-back reference accelerometer on a calibration shaker) to verify the sensitivity of accelerometers and the frequency response of vibration meters at defined frequencies (typically 80 Hz, 160 Hz, 1 kHz) and acceleration levels.
Key Takeaways
- Vibration calibration uses a precision shaker with a reference accelerometer (back-to-back method).
- Sensitivity calibration at 80 Hz or 160 Hz reference frequency per ISO 16063-21.
- Frequency response check across 10 Hz to 10 kHz bandwidth for vibration analysers.
- NABL-calibrated vibration instruments are essential for ISO 10816 machine vibration monitoring programs.
- Prism calibrates piezoelectric accelerometers, MEMS accelerometers, and handheld vibration pens.
Vibration Instruments Calibrated at Prism
- Piezoelectric accelerometers (charge and voltage output, ICP/IEPE type)
- MEMS accelerometers (low-frequency, DC-coupled)
- Handheld vibration meters / vibration pens (velocity RMS, acceleration, displacement)
- Vibration analysers and FFT spectrum analysers
- Machine vibration monitoring systems
- Shock sensors / shock accelerometers
ISO 10816 Machine Vibration Monitoring
ISO 10816 (now ISO 20816) defines vibration severity limits for rotating machinery: pumps, fans, compressors, motors, and turbines. The velocity RMS (mm/s) measured by vibration meters must be compared against ISO 10816 zones A/B/C/D to assess machine health. For this comparison to be valid, the vibration meter must be NABL-calibrated. Gujarat's heavy industries (refineries, chemical plants, power stations) rely on vibration monitoring programs that require calibrated instruments.
Vibration Meter Calibration Procedure
Back-to-Back Setup
Mount reference accelerometer and test accelerometer on vibration calibrator (precision shaker) using stud or adhesive mount.
Sensitivity Calibration
Apply defined vibration level at 80 Hz (or 160 Hz). Measure output of test accelerometer vs. reference. Calculate sensitivity in mV/g or pC/g.
Frequency Response Check
Sweep frequency from 10 Hz to 10 kHz (or 5 kHz for MEMS). Plot frequency response curve and check ±3 dB bandwidth.
Amplitude Linearity
Check linearity from 0.1 g to 100 g acceleration at reference frequency. Error must be < ±1%.
Certificate Issue
Issue NABL certificate with sensitivity value, frequency response chart, and expanded uncertainty.
Frequently Asked Questions
Why do accelerometers need regular calibration?
Piezoelectric crystals in accelerometers can lose sensitivity over time due to mechanical stress, temperature cycling, and overloads. A 10% sensitivity drift means all vibration readings are 10% incorrect, compromising predictive maintenance decisions.
How often should vibration meters be calibrated?
Annual calibration is the standard. Accelerometers used in high-shock environments or extreme temperatures should be calibrated every 6 months.
Can Prism calibrate vibration analysers with built-in accelerometers?
Yes. Prism calibrates complete handheld vibration analysers (make: SKF, CSi, Fluke, PRUFTECHNIK, Druck) as a system, including the built-in or external accelerometer.
What is the sensitivity of a typical piezoelectric accelerometer?
Typical ICP accelerometers have sensitivity of 10 mV/g to 100 mV/g. After calibration, the sensitivity is stated on the NABL certificate with ±0.5–1% expanded uncertainty.
Does vibration calibration require the accelerometer to be removed?
For laboratory calibration (back-to-back method), the accelerometer must be removed from the machine. For field calibration, an in-situ method using a reference handheld calibrator is possible but with higher uncertainty.
Written by
Er. Parthiv Kinariwala
Managing Director · Prism Calibration Centre · NABL CC-2480 · Ahmedabad
Er. Parthiv Kinariwala founded Prism Calibration Centre in 2004 and has over 20 years of hands-on experience in calibration engineering, NABL accreditation, and industrial compliance. His team performs 10,000+ calibrations annually from the Vatva GIDC laboratory, serving 5000+ industries across Gujarat.
Prism Calibration Centre — Vatva GIDC, Ahmedabad
Prism Calibration Centre
F-101, Rudraksh Complex 2, Phase 3, GIDC Vatva, Near Jasoda Nagar Cross Road, Ahmedabad — 382445, Gujarat, India
Phone: +91 98245 26444
Email: info@prismcalibration.com
NABL: CC-2480 · ISO/IEC 17025:2017
Hours: Mon–Sat, 9:00 AM – 7:00 PM