Linear position sensors such as LVDTs, LVITs, and potentiometers are capable of highly accurate and repeatable measurements—but only when they are installed correctly. Improper installation is one of the most common causes of measurement error, reduced repeatability, and premature sensor failure.
Below are some of the most common installation issues and how they impact performance.
Misalignment Between Sensor and Target
One of the most critical requirements for linear sensors is proper alignment.
The sensor core or shaft must move linearly and concentrically within the sensor body. If the motion is off-axis, even slightly, it can introduce:
- Measurement errors
- Increased friction or binding
- Accelerated wear (especially in contact sensors)
Best practice: Ensure the sensor and target are aligned along the same axis, and use mounting hardware that maintains alignment throughout the full stroke.
Side Loading on the Sensor
Side loading occurs when lateral forces are applied to the sensor shaft or core during operation.
This can lead to:
- Erratic readings
- Increased mechanical wear
- Reduced sensor life
This is especially problematic for potentiometer-style sensors, which rely on physical contact.
Best practice: Use rod-end bearings or guided mechanisms to isolate the sensor from side forces.
Improper Mounting Methods
Using incorrect mounting hardware or techniques can distort the sensor housing or affect internal operation.
Examples include:
- Tightening set screws directly onto the sensor body
- Uneven clamping force
- Using ferromagnetic mounting materials with inductive sensors
These issues can lead to:
- Signal distortion
- Reduced accuracy
- Mechanical damage
Best practice: Use split-collar mounting blocks or clamps that provide even, non-distorting support, and select non-ferromagnetic materials when required.
Incorrect Stroke Selection
Choosing a sensor with the wrong measurement range can negatively impact both accuracy and usability.
If the stroke is too short:
- The sensor may bottom out or saturate
If the stroke is too long:
- Resolution may be reduced
- Small movements may be harder to detect
Best practice: Select a sensor with a full-scale range that closely matches the expected motion.
Poor Electrical Connections
Improper wiring or low-quality connections can introduce noise or signal instability.
Common issues include:
- Loose connections
- Incorrect wiring
- Use of improper cables
- Lack of shielding in noisy environments
Best practice: Follow manufacturer wiring guidelines and use shielded cables when necessary.
Ignoring Environmental Factors
Temperature, vibration, moisture, and contamination can all affect sensor performance if not properly considered.
Examples include:
- Excessive vibration causing mechanical instability
- High temperatures affecting electronics
- Dust or debris interfering with moving components
Best practice: Select sensors rated for the environment and ensure proper protection or sealing where needed.
Over-Constraining the Sensor
Rigidly fixing both ends of a sensor without allowing for natural movement can introduce stress and misalignment during operation.
This can lead to:
- Binding
- Measurement error
- Mechanical damage over time
Best practice: Allow for slight flexibility in the mounting design to accommodate thermal expansion and mechanical tolerances.
Neglecting Calibration or Zeroing
Even with proper installation, failing to calibrate or zero the sensor can result in inaccurate measurements.
Best practice: Always verify output at known positions and perform calibration as needed for the application.
The Bottom Line
Linear sensors are precision devices, and their performance depends heavily on proper installation. The most common causes of inaccuracy—misalignment, side loading, improper mounting, and poor wiring—are all preventable with careful setup and attention to detail.
Need Help with Sensor Installation?
At HGSI, we design linear position sensors for high accuracy and long-term reliability—but correct installation is key to getting the most out of your system.
If you need assistance selecting or installing the right sensor for your application, CONTACT US now!