Accelerometers: Applications and Techniques for Vibration Measurements
Accelerometers are core transducers used to measure vibration and acceleration across industrial, automotive, structural, and consumer applications. Accurate vibration measurement depends on correct accelerometer selection, mounting, calibration, data acquisition, and analysis. When properly applied, accelerometers deliver defensible vibration data for design validation, operational monitoring, and maintenance decision-making.
What Is an Accelerometer?
An accelerometer is a transducer that measures vibration by detecting the acceleration of motion in a structure. It converts mechanical vibration into a proportional electrical signal, in accordance with Newton’s Second Law of Motion, which states that acceleration (m/s²) is directly proportional to the net force acting on a body and inversely proportional to its mass.
Accelerometers measure acceleration indirectly by detecting the force applied along one or more sensing axes. A common sensing approach is capacitance-based measurement, where acceleration causes a mass to move, changing capacitance. Other accelerometers use different mechanical and electrical transduction principles depending on design.
Different accelerometer types, such as piezoelectric, MEMS, piezoresistive, and strain gauge accelerometers, use different constructions optimized for specific frequency ranges, amplitudes, and applications.
Types of Accelerometers
Piezoelectric Accelerometers
Piezoelectric accelerometers use a sensing crystal with an attached seismic mass. When acceleration occurs, the mass applies force to the crystal, generating an electrical charge proportional to acceleration.
- High-impedance output signal
- Suitable for industrial vibration measurements
- Well suited for high-frequency applications
Widely used in machinery condition monitoring and structural vibration
MEMS (Microelectromechanical Systems) Accelerometers
MEMS accelerometers are manufactured using microfabrication techniques on silicon.
- Detect acceleration via changes in capacitance
- Compact, low power, and robust
- Widely used in consumer electronics, automotive safety, and low-frequency vibration measurements
Typical applications include smartphones, automotive airbags, motion tracking, and seismic sensing.
Piezoresistive Accelerometers
Piezoresistive accelerometers use materials whose electrical resistance changes under mechanical stress.
- Similar in principle to strain gauges
- Suitable for high-bandwidth and short-duration events
- Commonly used in crash testing and impact measurements
Strain Gauge Accelerometers
Strain gauge accelerometers use strain gauges bonded to a deformable structure. Acceleration causes deformation, changing resistance measured via a bridge circuit.
- Ideal for static and low-frequency acceleration
- Common in automotive safety systems, including ABS and traction control
- Suitable for long-duration acceleration measurement
Main Applications of Accelerometers
Designing Systems
- During R&D, accelerometers validate performance and safety:
- Automotive safety: MEMS and piezoresistive accelerometers test airbags, ABS, traction control, and crash behavior
- Consumer electronics: MEMS accelerometers enable screen rotation, motion gaming, fitness tracking, and interface design
- Aerospace and defense: Piezoelectric and MEMS accelerometers support navigation, stability control, inertial guidance, and structural health monitoring
Operation
- During live operation, accelerometers provide real-time functionality:
- Automotive systems detect rapid deceleration to deploy airbags
- Consumer electronics use accelerometers for orientation and motion sensing
- Seismic monitoring systems detect and record ground motion
- Industrial machinery uses piezoelectric accelerometers to detect imbalance, looseness, and operational instability
Maintenance
- For maintenance and condition monitoring:
- Predictive maintenance: Piezoelectric and strain gauge accelerometers identify early failure indicators
- Structural health monitoring: Strain gauge and capacitive accelerometers monitor bridges, buildings, and dams
- Vehicle health monitoring: MEMS and piezoresistive accelerometers detect vibration and shock events indicating wear or damage
Using Accelerometers for Vibration Measurements
Using accelerometers effectively requires technical discipline:
- Correct mounting and orientation
- Proper calibration
- Correct data acquisition settings
Accelerometers are connected to a vibration meter, and environmental conditions such as temperature and humidity must be considered to maintain accuracy.
Devices That Use Accelerometers
Accelerometers form part of the measurement chain of vibration meters, which includes:
- Power supply
- Cables
- Connectors
Proper powering is essential for accurate measurements. High-quality cables and connectors ensure reliable signal transmission and minimize data loss.
Vibration meters may be single-channel or multichannel, and accelerometers are available in single-axis and triaxial configurations.
How to Choose the Right Accelerometer
Frequency range (Hz)
Defines the vibration frequencies the accelerometer can measure. For vibration severity measurement, ranges commonly include 10 Hz to 1,000 Hz, though some ISO 20816 applications specify cut-offs as low as 2 Hz.
Dynamic range (g)
Maximum measurable acceleration without distortion or clipping.
Sensitivity (mV/g or mV/(m/s²))
Electrical output per unit acceleration, typically specified at a reference frequency.
Temperature range
Environmental limits the accelerometer can withstand.
Mass
Sensor mass can influence measurement accuracy, especially on lightweight structures.
Mounting type
Stud, adhesive, or magnetic mounting options.
Compatibility with the vibration meter
Ensures seamless integration and correct signal conditioning.
Ensuring Accelerometer Accuracy
Accuracy requires:
- Initial laboratory calibration
- Periodic recalibration every two years
Calibration compares accelerometer output against traceable reference standards.
Regular in-situ verification using handheld vibration calibrators (e.g., SV110) is also essential to maintain measurement confidence over time.
Mounting Accelerometers
Correct mounting is critical for accurate vibration measurement. Common mounting methods include:
- Stud mounting
- Adhesive mounting (cement or wax)
- Magnetic mounting
Secure attachment minimizes resonance, motion loss, and interference, ensuring the accelerometer accurately captures vibration.
Collecting Vibration Data from Accelerometers
Data acquisition requires configuring the vibration meter to:
- Select appropriate sampling rate
- Define data logging parameters
- Choose result types such as:
- PEAK
- RMS
- MAX
- PEAK-PEAK
- VDV
- PEAK
- Perform frequency analysis (FFT or 1/3 octave)
- Record raw time data (WAV)
Correct configuration prevents data loss and ensures diagnostic value.
How to Measure FFT
Collected data must be processed using specialized software. Tools such as SvanPC++ apply filters and algorithms to extract:
- Vibration amplitude
- Frequency content
- Spectral characteristics
This processing transforms raw data into actionable information.
Interpreting Data and Making Adjustments
The final step is interpreting processed results to assess the condition of machinery or structures.
Based on analysis, engineers and technicians can:
- Improve system performance
- Prevent failures
- Adjust operating parameters
- Ensure safety and compliance
Our Methodology - How We Work With You
Step 1
Discovery
We begin by learning details of your projects, including timeframe, regulations, potential issues, budget and other requirements
Step 2
Development
Once we understand your needs, we develop a turnkey, solution with hardware and software, keeping both the budget and timeframe in mind.
Step 3
Implementation
We support you every step of the way, providing hands-on equipment and software training for your team to ensure that your monitoring program is successful
Request Quote
For Sales, Rentals, and Quotes, please get in touch with us by filling out the form below. Our knowledgeable staff is ready and eager to assist you!