Introduction
Torque measurement is essential in modern industry—from automotive R&D to smart manufacturing and robotic control. Selecting the correct torque sensor ensures measurement accuracy, enhances system performance, and prevents costly mechanical failures.
This article provides a clear and practical guide to choosing the most suitable torque sensor for your needs.
1. What Is a Torque Sensor?
A torque sensor (also called a torque transducer) measures the rotational force applied to a component or shaft. It converts mechanical torque into an electrical signal that can be analyzed or recorded.
Torque sensors are used in a wide variety of systems, including:
Electric motors
Gearboxes and transmissions
Fastening tools
Test benches
Robotic arms
2. Static vs. Dynamic Torque Sensors
🔹 Static Torque Sensors
These measure torque in non-rotating systems or during limited angular motion. They are often used in calibration setups, torque tool verification, or lab environments where precision is critical.
🔹 Dynamic (Rotary) Torque Sensors
These are used in systems with continuous rotation, such as motors, drives, or test rigs. They allow real-time measurement of torque during high-speed rotation, and often support output of both torque and rotational speed.
3. Key Factors to Consider When Choosing a Torque Sensor
✅ Torque Range
Always select a sensor with a measuring range that comfortably exceeds your maximum expected torque. A safety margin (e.g., 150%) is recommended for overload protection.
✅ Output Type
Common signal outputs include:
Analog (0–10V, 4–20mA)
Digital (RS485, CANopen)
Charge output (for piezo-based designs)
Choose one that’s compatible with your existing DAQ system or controller.
✅ Shaft Speed
For rotating systems, check the sensor’s rated speed (some support up to 25,000 rpm). Ensure it meets your operational requirements.
✅ Mounting Configuration
Common types include:
Flange-to-flange
Shaft-through
Keyed or spline connections
Pick one that integrates easily with your mechanical setup.
✅ Environmental Conditions
Consider:
Operating temperature range
IP rating (e.g., IP65 for dust/water resistance)
Vibration and shock resistance
4. Common Applications by Industry
| Industry | Typical Usage Example |
|---|---|
| Automotive | Torque measurement in engine and powertrain development |
| Aerospace | Actuator torque testing and vibration monitoring |
| Robotics | Joint torque feedback and motion control |
| Manufacturing | Tool torque validation and quality control |
| Energy | Generator shaft torque monitoring |
5. Common Pitfalls to Avoid
Using a sensor too close to its maximum range: may reduce accuracy and increase risk of overload.
Ignoring mechanical misalignment: can lead to sensor fatigue or signal distortion.
Neglecting calibration: torque sensors require periodic calibration to maintain accuracy.
6. Final Thoughts
Torque sensors are critical components in precision control and measurement. A good match between sensor type and application ensures reliable performance, extended equipment life, and better process insight.
If you’re unsure which type of torque sensor fits your system, consult an instrumentation engineer or refer to standards like ISO 6789 (torque tool calibration) or DIN 51309 (calibration of torque measuring devices).