Overview
ISO/TS 17242:2014 defines a quasi-static calibration procedure for seat belt force transducers (belt force transducers) with loading capacities up to 25 kN. Its objective is to standardize test specifications and sequences so measurement results are comparable between testing laboratories. The technical specification covers test setup, environmental conditioning, data acquisition, and reporting requirements for traceable, repeatable calibration of belt force sensors used in restraint-system testing and development.
Key topics and technical requirements
- Scope and device types: Applies to belt force transducers (Types 1–4) with defined design categorizations (baffle, loop, clamping, 3‑bolt). Standardized calibration belt strap is recommended for many Type 1 applications; absolute-value calibration may require the actual seat belt webbing designated for subsequent tests.
- Load capacity: Calibrations up to 25 kN full-scale.
- Test method: Continuous loading to full scale; single loading sequence up to 101% of calibration range.
- Mechanical setup:
- Free clamping length: 375 mm ± 75 mm.
- Test velocity: 170 mm/min ± 30 mm/min.
- Use of standardized belt strap (Annex C) recommended; belt type and average thickness must be recorded.
- Data acquisition & evaluation:
- Minimum sampling rate: 100 Hz for first loading sequence.
- Filter settings in accordance with ISO 6487.
- Evaluation interval: 2% to 100% of calibration range.
- Regression options: linear (least-squares through origin) or third-degree polynomial (least-squares); zero-offset handling differs (linear: zero corrected prior to test; polynomial: zero not corrected).
- Reported outputs: sensitivity in kN/mV/V and mV/kN/V (linear) or polynomial coefficients (F = AS^3 + BS^2 + CS + M).
- Environment & conditioning:
- Temperature: 19 °C – 23 °C, Relative Humidity: 10% – 70%.
- 8 h acclimatization recommended for transducers and belt strap prior to calibration.
- Documentation: Calibration report must include temperature, humidity, belt strap type and thickness, excitation voltage/pin assignment, measured sensor offset, sensitivity or polynomial coefficients, and nonlinearity (% of calibration range).
Applications
- Ensures inter‑laboratory comparability of belt force measurements used in occupant restraint testing, crash test development, and safety validation.
- Supports calibration for sensors used in crash test dummies, vehicle restraint system R&D, certification testing, and metrology labs that provide traceable force measurement services.
- Useful during development efforts where consistent quasi-static characterization of belt load transducers is required.
Who should use this standard
- Automotive test laboratories and accreditation bodies
- OEM safety engineers and product developers
- Metrology and calibration service providers
- Crash test facilities and instrumentation engineers
Related standards
- ISO 376 (force-proving instruments)
- ISO 6487 (impact test instrumentation)
- ISO 13499 (multimedia data exchange for impact tests)
- SAE J2517 (related calibration practice)
- ECE‑R16 (seat belt fixations and requirements)
Keywords: ISO/TS 17242:2014, belt force transducers, quasi-static calibration, seat belt force transducers, calibration procedure, testing laboratories, calibration belt strap.