5 Steps to Create an Effective Quality Assurance Program for Test Sieves
Everyone desires the longevity of their sieves, ensuring they adhere to the relevant standards. NL Scientific Test Sieves assure adherence to ASTM or ISO s tandards for Inspection, Compliance, or Calibration grades right from the point of acquisition. However, over time, issues like wire cloth s tretching, sagging, tearing, or ch anges in wire diameter due to abrasive materials can alter opening sizes. The question then arises: How can you replace your sieves proactively? The solution involves implementing a continuous, internal quality control initiative, and we'll lead you through the process in five simple stages.
Step 1: Establishing a Master Set
Begin your quality assurance initiative by setting up a designated Master Reference Set, consisting of Calibration or Inspection test sieves. This Master Set serves as the benchmark for evaluating Working Sieves, monitoring wear, and planning replacements. Inspection and Calibration grade sieves come with detailed verification documentation, ensuring their conformity with the rigorous standards defined by the American Society for Testing and Materials (ASTM) or the International Organization for Standardization (ISO). To ensure precise record-keeping, consider using a system aligning with your organization's protocols, enabling straightforward access during routine assessments and audits.
Step 2: Developing Comparative Working Sieve Sets
For everyday testing, utilize Working Sieve Sets. Regularly compare them to the Master Set to identify the core at which working Sieves deviate from the specified s tandards. This approach optimizes the longevity of Working Sieves, reduces the need for external verification, and, crucially, safeguards against inaccurate, imprecise, or unr eliable test outcomes. When assessing the performance of sieves as a complete stack, ensure they are always evaluated as a unified unit by documenting the serial number of each sieve and cross-referencing them before any comparison. A single misplaced sieve can jeopardize the integrity of the entire set. Additionally, assess individual sieves by comparing them individually to their corresponding Master Sieve.
Step 3: Performing Comparisons for Each Working Sieve Set
Perform comparative assessments on Working Sieve Sets to identify sieves that fall outside the established tolerance range, indicating the need for replacement. The primary evaluation between Master and Working Sieve Sets creates a foundational reference point. As Working Sieves undergo wear, subsequent evaluations reveal increased deviations from their initial comparison with Master Sieves. For example, if the initial comparison shows a 1.5% deviation between the Working No.10 sieve and the Master No. 10 sieve, this percentage of d eviation is most likely to rise with time. Once it is reaching 3.5% (a 2% or m ore increase), it may be deemed unsuitable for further use. Quality Assurance programs generally consider an acceptable variation of ±1% to 3% from the Master Sieve as the standard.
Step 4: Employing Standard Reference Materials When Required
Utilizing user-prepared materials, while aligning with your regular work, presents challenges as they are non-standard and demand extensive handling for preparation. Replicating and verifying these materials for routine re-evaluations can be complex. A viable choice is Standard Reference Materials (SRMs), consisting of accurately sized glass beads or powders created to assess sieve efficiency and establish precise opening dimensions. Crafted using equipment with traceability to the National Institute of Standards and Technology (NIST) or the European Community Bureau of Reference (BCR), SRMs ensure consistency and dependability. Despite their relatively higher cost, SRMs prove invaluable in enhancing your internal quality control program, seamlessly integrating into existing processes.
Step 5: Remember, Quality Assurance Is an Ong oing Process
Creating an in-house quality assurance initiative starts with establishing a foundational Master Set comprising new Inspection or Calibration sieves, serving as the gold standard for comparisons. This initial benchmarking is crucial and requires utmost precision. Building the Working Sets necessitates the use of pristine Compliance Grade sieves, emphasizing the need for unwavering dedication, meticulous record-keeping, and attention to every detail, including visual inspections before deployment. Thorough cleaning prior to storage holds equal significance. Regular inspections and performance evaluations, seamlessly integrated into your quality control protocols, offer a reliable gauge of a test sieve's precision and adherence to ASTM or ISO criteria. With these essential components in play, the timely replacement of sieves can be confid ently managed.
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