Vibration measurement devices: IEPE accelerometers, velocity transducers, proximity sensors

Introduction: The Importance of Vibration Measurement Devices for Production Reliability

Vibration measurement devices are critical components of control and monitoring systems in industrial installations. Their main function is to detect vibration processes occurring in mechanical systems to ensure their safety, durability and efficiency. Vibration measurement devices are used for detecting deviations in equipment operation, identifying fatigue stresses, detecting wear, as well as for predicting failure. Therefore, proper selection, installation and monitoring of vibration measurement devices are necessary to ensure production reliability.

Fundamental principles: physics and mechanics of vibration measurement

Vibration measurement devices operate based on the principle of measuring vibration, which is the motion of a body with variable velocity. Vibration can be measured as velocity, acceleration or displacement. According to this, vibration measurement devices are divided into three main types: IEPE accelerometers, velocity transducers and proximity sensors.

IEPE accelerometers use signal conditioners with output voltage signals proportional to acceleration. Velocity transducers measure vibration velocity, and proximity sensors measure changes in distance between surfaces, allowing the detection of vibration at very low levels.

Technical specifications and standards

Vibration measurement devices must be manufactured in accordance with the following standards:

• IEPE (Integrated Electronic Piezoelectric) — standard defining signal conditioners used in accelerometers. Compliance with IEPE 1424 ensures harmonious measurement signals.
• ISO 281 — establishes the standard for measuring acceleration, velocity and displacement of vibration.
• DSTU 4814-99 — establishes requirements for measuring equipment used in Ukrainian industrial production.
• EN 50081 — establishes electromagnetic compatibility for measuring devices.
• IEC 60947-2 — establishes requirements for electrical devices used in industrial systems.

Selection criteria for vibration measurement devices include:

• Measurement range (for example, 0–500 Hz, 0–1000 Hz)
• Measurement accuracy (for example, ±0.5%, ±1.0%)
• Output signal (for example, 0–10 V, 4–20 mA)
• Maximum operating temperature (for example, -40°C to +85°C)
• Power consumption (for example, 10 mA, 5 V)

Selection criteria and calculation

The selection of a vibration measurement device depends on the type of measurement, operating conditions, and requirements for accuracy. Below is a table that helps determine the optimal option for a vibration measurement device.

Practical advice on installation and commissioning

Proper installation and commissioning of vibration measurement devices play a key role in ensuring their reliability and accuracy:

1. Installation Location Selection — the selection of location should ensure a stable connection to the equipment and absence of external influences (heat, moisture, magnetic fields).
2. Connection — use cables with high electromagnetic interference immunity and compliance with standards IEC 60947-2.
3. Setup — adjust the parameters of the measuring device according to the manufacturer's data and operating conditions.
4. Testing — conduct testing before use to ensure compliance with standards requirements.
5. Monitoring — regularly check the condition of the device and measurements to ensure accuracy.

Modal Failures and Cause Analysis

Most common failures of vibration measurement devices include:

• Vibration Increase — indicates possible wear or fatigue failure.
• Signal change — may be caused by humidity, contamination or electromagnetic influences.
• Instability — occurs due to incorrect installation or instability of the input signal.
• Parameter Change — may be caused by temperature influences or changes in vibration parameters.

Failure cause determination may include the use of visual indicators, data analysis, and execution of diagnostic tests.

Fatigue Prediction and Condition Monitoring

Modern methods of fatigue prediction and condition monitoring measure vibration parameters to detect possible failures. The following methods are used:

• Signal Filtering — is used for noise removal and improving measurement accuracy.
• Frequency Analysis — is used for detecting deviations in the frequency spectrum.
• Temperature Monitoring — is used for detecting the influence of temperature on the device.
• Computer processing — is used for analyzing data and predicting fatigue.

These methods ensure high accuracy and efficiency of measurements, meeting the requirements of standards.

Comparison table

The following is a comparative table showing the differences between three vibration measurement devices.

Conclusion

Vibration measurement devices are essential components for ensuring the reliability and efficiency of industrial equipment. Proper selection, installation, and monitoring of vibration measurement devices play a key role in ensuring their continuous operation. Unitec-D (UNITEC-D) is a reliable supplier of vibration measurement devices that meet the requirements of standards and provide high measurement accuracy. For complete information on available vibration measurement devices, visit https://www.unitecd.com/e-catalog/.

Sources

• ISO 281 — Vibration Measurement
• DSTU 4814-99 — Requirements for Measuring Equipment
• IEC 60947-2 — Requirements for electrical equipment
• EN 50081 — Electromagnetic Compatibility
• UNITEC-D Technical Data Sheet — Manufacturer's Documentation