NEWS

Flange force sensors are widely used in industrial applications to measure clamping force, compression, and preload in bolted joints, flanged connections, and mechanical assemblies. Their ability to provide real-time feedback is critical for ensuring safety, performance, and reliability. However, in practice, users sometimes encounter unstable or fluctuating readings, which can compromise system accuracy and operational efficiency. Understanding the common causes of unstable readings can help engineers and technicians maintain precise force measurement.

1. Improper Installation or Alignment

One of the most frequent causes of unstable readings is incorrect installation. Flange force sensors are designed to measure pure axial force. If the sensor is misaligned, tilted, or subjected to bending moments, the load is distributed unevenly across the sensing element, resulting in inconsistent output.

Proper installation requires:

• Aligning the sensor concentrically with the bolt or flange axis.

• Ensuring flat, rigid mounting surfaces free from debris, oil, or burrs.

• Using recommended washers or load distribution plates to prevent localized stress.

2. Side Loads and Shear Forces

Flange force sensors are sensitive to off-axis loads. Any lateral force, shear, or torque applied to the sensor can introduce noise and fluctuations. Vibrations from nearby machinery or uneven tightening of bolts can also generate side forces that affect measurement stability.

Mitigation strategies include:

• Installing guides or supports to restrict lateral movement.

• Using vibration damping materials or mounts in high-vibration environments.

3. Environmental Factors

External environmental conditions play a significant role in sensor stability. Temperature fluctuations can cause expansion or contraction of metal components, altering the stress on the sensor. Moisture, dust, or corrosive substances can degrade sensor performance or insulation.

To reduce environmental impact:

• Select sensors with appropriate temperature compensation.

• Use IP-rated sensors for dust and water protection.

• Ensure regular cleaning and maintenance in harsh environments.

4. Electrical Interference and Signal Issues

Flange force sensors generate small electrical signals, which can be affected by electromagnetic interference (EMI) or poor cable management. Loose connections, damaged cables, or proximity to high-voltage equipment can introduce signal noise and lead to unstable readings.

Best practices include:

• Using shielded cables and proper grounding.

• Routing cables away from motors, inverters, or high-power lines.

• Ensuring secure connections at both the sensor and data acquisition system.

5. Overloading or Mechanical Fatigue

Applying force beyond the rated capacity of the sensor can cause temporary or permanent deformation of the sensing element. Even if the sensor continues to produce readings, accuracy may be compromised, resulting in instability.

Regular inspection and selecting a sensor with sufficient overload margin are essential for long-term reliability.

6. Lack of Calibration or Maintenance

Sensor drift over time is another cause of unstable readings. Mechanical wear, joint relaxation, or changes in preload can affect output. Without periodic calibration and maintenance, these factors accumulate, leading to fluctuating measurements.

Conclusion

A combination of mechanical, environmental, and electrical factors typically causes unstable readings from a flange force sensor. Proper installation, careful alignment, protection from side loads, and routine calibration are key to achieving reliable performance. By understanding and addressing these potential issues, engineers and operators can ensure accurate force measurement, enhance operational safety, and extend the lifespan of flange force sensors in industrial applications.