| Material identity and grade | Material specification and lot-specific certificate of analysis (CoA) | Compare the stated quartz or fused-silica grade and composition with the purchase specification; confirm the certificate refers to the supplied lot. | Clearly stated material type, applicable properties, test results, units, lot identifier, and acceptance limits agreed for the application. |
| Quality management controls | Quality-system certificate, inspection procedures, nonconformance process, and corrective-action records | Check certificate validity and scope with the issuing certification body; ask how out-of-specification material is identified and contained. | Documented, repeatable controls and records for inspection, handling of nonconformances, corrective actions, and change notification. |
| Dimensional inspection | Inspection report for dimensions, tolerances, and relevant geometric features | Compare reported measurements with the drawing and agreed tolerance; confirm the measurement equipment is calibrated and suitable for the tolerance. | Measured values, units, tolerance limits, sampling details, inspection date, and equipment or method identification. |
| Optical transmission | Spectral transmission report, when optical performance is required | Review the wavelength range, sample thickness, surface condition, and measurement setup; compare results only with a specification using the same conditions. | Transmission reported against wavelength, with specimen thickness and test conditions stated. No single transmission limit applies to every quartz-glass grade or application. |
| Impurity and hydroxyl (OH) analysis | Elemental impurity results and, where relevant, hydroxyl-content results | Ask for the analytical technique, detection or quantification limits, units, and sample preparation. Elemental analysis may use methods such as ICP-OES or ICP-MS; OH content may be assessed by infrared spectroscopy. | Results tied to the supplied material or lot, with methods and limits stated. Required limits should be defined for the intended use rather than assumed to be universal. |
| Bubbles, inclusions, and surface condition | Visual-inspection criteria, inspection records, and defect images where appropriate | Confirm lighting, viewing conditions, inspected area, defect definitions, and acceptance criteria before production or shipment. | A consistent inspection procedure and clearly agreed limits for bubbles, inclusions, scratches, chips, and other relevant defects. |
| Thermal performance | Property data or test results for the specific thermal requirement, if applicable | Verify the property measured, test method, specimen condition, and temperature range; distinguish material data from finished-part performance. | Application-relevant data, such as a specified thermal property or validated thermal-cycle result, with test conditions documented. |
| Lot and process traceability | Lot-number system, production records, and shipment documentation | Select a shipped item and trace its identifier back to the material lot, inspection records, and relevant production or processing records. | Consistent identifiers linking the product, CoA, inspection results, and shipment; records should be retained for an agreed period. |
| Laboratory competence | Laboratory accreditation details or method-validation and calibration records | For critical tests, check whether an external laboratory is accredited to ISO/IEC 17025 for the relevant test and measurement range; accreditation alone does not cover every test. | Test results from a competent laboratory using a method suitable for the required property and reporting range. |
| Packaging and contamination prevention | Packaging specification, handling procedure, and shipment inspection records | Check that packaging protects the part from impact, abrasion, moisture, and contamination risks relevant to its geometry and use. | Packaging and handling requirements agreed in advance, with clear part identification and a process for reporting transit damage. |
| Change control and ongoing consistency | Written change-notification policy and periodic quality data | Ask how changes to material source, process, equipment, or test method are reviewed and communicated before implementation. | Advance notification for changes that could affect agreed requirements, with requalification or approval steps defined when needed. |