AMS2750G to AMS2750H: Key Changes in Pyrometry Requirements
The aerospace industry demands strict control over heat treatment processes to ensure the safety and performance of critical components. To regulate these processes, the AMS2750 standard outlines comprehensive pyrometry requirements for equipment calibration, testing, and temperature uniformity. The latest revision, AMS2750H, introduces several important changes from AMS2750G, reflecting technological advancements and clarifying requirements to maintain high standards in thermal processing. Below is an outline of the key differences and updates.
1. Definitions and Clarifications
AMS2750H provides updated definitions and clarifications, improving understanding and application of the standard:
- New and Updated Definitions: Changes in terms like Sensor Calibration, System Accuracy Tests (SAT) and Temperature Uniformity Surveys (TUS) have been introduced to clarify requirements. Specifically, more precise definitions for SAT and TUS sensor reuse have been added, which provide better guidelines for their implementation.
- Sensor Reuse and Recalibration: AMS2750H includes updates on sensor reuse and recalibration frequency, refining how expendable and nonexpendable sensors are managed depending on their exposure to specific temperatures and their lifespan.
2. Sensor Calibration and Reuse
- New Calibration Points: AMS2750H now requires calibration points at more frequent intervals (≤ 250 °F/140 °C) across a wider temperature range. This modification helps ensure that pyrometric instruments maintain higher accuracy during prolonged usage.
- Recalibration Intervals: The recalibration intervals for nonexpendable base metal sensors used above 500 °F have become more stringent in AMS2750H, with additional clarity on allowable temperature deviations and the impact on calibration cycles.
3. Instrumentation Requirements
- Digital Instrumentation: Both versions emphasize the importance of digital instrumentation, but AMS2750H introduces more detailed requirements for accuracy and calibration methods, including requirements for digital records and timestamps. Additionally, AMS2750H allows more flexibility with wireless transmitters, improving data collection and monitoring capabilities.
- Calibration Accuracy and Traceability: AMS2750H maintains stringent accuracy requirements but increases the importance of calibration traceability and the need for using primary and secondary standards. Instruments must be calibrated quarterly or semi-annually, depending on the furnace class, with stricter protocols to ensure their precision.
4. Temperature Uniformity Survey (TUS)
- TUS Data Collection Requirements: AMS2750H updates the data collection frequency requirements for TUS, ensuring that data points are collected at sufficient intervals to demonstrate uniformity. The revised standards also address the treatment of temperature deviations during surveys and how adjustments should be managed and documented.
- Sensor Placement: AMS2750H improves guidance on sensor placement during TUS, clarifying how sensors should be positioned to ensure accurate readings across the qualified work zone.
5. System Accuracy Test (SAT) Updates
- Comparison SAT: A new provision in AMS2750H is the introduction of comparison SAT requirements for improved accuracy checks. These updates provide more options for SAT frequency, allowing facilities to adjust based on operational needs while maintaining compliance.
- Alternative SAT Frequency: AMS2750H introduces flexibility in SAT testing frequency under certain conditions, with clearer guidelines on how to apply waivers and alternate methods. This change reflects the growing use of advanced monitoring technologies that can reduce the need for frequent physical tests.
6. Documentation and Record-Keeping
- Electronic Record Management: AMS2750H enhances electronic record-keeping requirements, ensuring all digital records are tamper-proof and aligned with modern data acquisition systems. This helps ensure compliance with industry standards and audits, providing more transparency and accountability.
Key Takeaways on the Transition from AMS2750G to AMS2750H
Transitioning from AMS2750G to AMS2750H involves updating procedures, particularly around sensor calibration, system accuracy tests and temperature uniformity surveys. The updates in AMS2750H reflect a move toward more rigorous documentation, greater sensor reuse management and flexibility in calibration frequencies, ensuring that aerospace thermal processing continues to meet stringent safety and performance requirements. These changes, while adding complexity, ultimately lead to more accurate, reliable and efficient heat treatment processes.
To get ready for AMS2750H, reach out to the experts at Conrad Kacsik. We offer training courses that help you meet the AMS2750 standard and Nadcap requirements. These courses make compliance simpler to understand and easier to achieve.
On top of this, we offer calibration services and process certification services that will help you meet the most demanding industry standards, including AMS2750H. Talk to an expert today to learn more.