The Best Ways to Choose a Right Torque Sensor?
A systematic evaluation of technical parameters, environmental adaptability, installation conditions, and cost-effectiveness is required. Below is a detailed step-by-step guide:
1. Define Measurement Requirements
- Measurement Range
- Select a sensor with a range 20%-30% higher than the maximum expected torque (e.g., for 100N·m max torque, choose 120-130N·m).
- Excessive range reduces accuracy; insufficient range risks overload damage.
- Accuracy Class
- High precision (±0.1%~0.5%): R&D, aerospace, precision manufacturing.
- Industrial grade (±1%): Production line monitoring, general testing.
- Static vs. Dynamic Torque
- Static torque: Slow or fixed loads (e.g., bolt tightening).
- Dynamic torque: High-speed rotation or transient loads (e.g., motors, drive shafts); requires attention to response frequency (typically ≥10× the measured signal frequency).
2. Evaluate Environmental Conditions
- Temperature
- Standard sensors: -20℃ to 60℃.
- Extreme environments: High-temperature models (up to 150℃) or low-temperature models (below -40℃), using stainless steel or special alloys.
- Humidity/Corrosion
- Humid/chemical environments require IP67 or higher protection, with sealed materials like stainless steel or coated finishes.
- Vibration & Shock
- Heavy machinery (e.g., excavators) needs sensors with shock-resistant designs (e.g., MIL-STD-810G compliant).
3. Installation & Mechanical Compatibility
- Mounting Options
- Flange-mounted: Easy installation, suitable for spacious setups.
- Shaft-mounted: Directly embedded in rotating shafts, space-saving; may require slip rings (wireless transmission avoids slip ring wear).
- In-line: Connected in the drivetrain; shaft alignment tolerance must be <0.1mm.
- Size & Weight
- Compact spaces: Micro sensors (e.g., outer diameter <20mm). Lightweight applications (e.g., drones): Aluminum alloy housings.
4. Signal Output & Integration
- Output Types
- Analog (4-20mA/0-10V): Compatible with traditional PLC systems; prone to interference.
- Digital (CAN bus/RS485): Ideal for long-distance transmission or Industrial IoT (IIoT).
- Wireless (Bluetooth/Wi-Fi): Suitable for rotating parts or hard-to-wire scenarios.
- Power Supply
- Standard 24VDC or battery-powered (low-power designs extend wireless sensor life).
5. Performance & Reliability Verification
- Long-Term Stability
- Check manufacturer's drift specifications (e.g., <0.1%/year); prefer models with self-calibration.
- Dynamic Response
- High-frequency applications (e.g., motor testing) require response time <1ms and bandwidth ≥1kHz.
6. Cost & Supply Chain
- Total Cost of Ownership (TCO)
- Includes procurement, installation, and maintenance. Example: Wireless sensors may have higher unit costs but save wiring expenses.
- Brand & After-Sales Support
7. Industry Certifications & Compliance
Key Certifications
- Automotive: ISO/TS 16949.
- Medical: ISO 13485.
- Explosive Environments: ATEX/IECEx (for oil/gas, chemical industries).
