Overview
EN ISO 19675:2024 (identical to ISO 19675:2017 and adopted by CEN) defines the specification for a steel calibration block used to calibrate phased array ultrasonic testing (PAUT) equipment. The standard sets requirements for block material, heat treatment, dimensional tolerances, surface finish, internal quality, reference marks, velocity and attenuation checks, marking and manufacturer declaration of conformity. It is intended to ensure consistent, reproducible PAUT calibration across industry.
Key topics and technical requirements
- Scope: Calibration block for ultrasonic testing with the phased array technique (PAUT).
- Material: Steel grade S355J0 (EN 10025-2) or equivalent.
- Pre‑machining and heat treatment:
- Raw block rough-machined to 320 × 120 × 30 mm before heat treatment.
- Heat treatment sequence: austenitizing at 920 °C for 30 min, quench in water, temper at 650 °C for 3 h, then cool in still air.
- Recommended pre-machine size prior to final machining: 305 × 101 × 26.5 mm.
- Internal quality / isotropy:
- Ultrasonic straight‑beam probe (≥10 MHz, transducer size 10–15 mm) used to check for internal discontinuities on all long faces. Grain scatter noise set to 10% of full-screen height (FSH); no echo above grain scatter level.
- Isotropy for longitudinal and transverse wave velocities verified per Annex A (velocity measurements).
- Attenuation check: Practical criterion-observation of multiple back-wall echoes (at least four echoes above 25% FSH with recommended probe).
- Final machining and tolerances:
- Surface roughness ≤ 0.8 μm Ra; pre-machined ≤ 1.6 μm Ra.
- Overall block size tolerance ± 0.1 mm; reflector and hole tolerances specified (e.g., hole diameters ±0.2 mm, angles ±1°).
- Reference marks and marking:
- Permanent, shallow engraved marks (~0.1 mm max), preferably etched or laser‑engraved (no stamping).
- Block must be marked with the document reference, manufacturer serial number/trademark and steel grade.
- Documentation: Manufacturer issues a declaration of conformity including measured dimensions, attenuation results and velocity measurements.
- Modifications allowed: Blocks thicker than 25 mm permitted to accommodate larger probe apertures.
Applications and users
- Primary users: NDT/PAUT technicians, calibration block manufacturers, ultrasonic equipment vendors, welding and inspection engineers, and QA/QC teams.
- Typical industries: oil & gas, power generation, petrochemical, pressure-vessel fabrication, aerospace, pipeline inspection and any sector using PAUT for weld and component inspection.
- Uses include: equipment setup, probe characterization, beam-angle verification, sensitivity checks and training/qualification of operators.
Related standards
- ISO 5577 - Ultrasonic testing vocabulary
- EN 16018 - Terms used in ultrasonic testing with phased arrays
- EN 10025-2 - Technical delivery conditions for S355J0 steel
Keywords: EN ISO 19675:2024, PAUT calibration block, phased array testing, ultrasonic testing calibration block, S355J0, ultrasonic calibration, NDT standards.
