Variable Acceptance Sampling for Transverse Finish Uniformity
Variable acceptance sampling under ISO 3951 verifies transverse finish uniformity by testing continuous mass add-on against statistical tolerance limits.
S-Method
Deviation Assessment
Statistical procedure provides a framework for accepting or rejecting a batch of textiles based on the standard deviation of a sample. Utilizing the s-method requires measuring a specific number of items and calculating their variability to ensure they meet a technical requirement. This approach is common in tests for yarn count or bursting strength where numerical data is collected.
Sampling Logic
The method assumes that the property being measured follows a normal distribution within the production lot. It offers a more efficient alternative to testing every single item while still providing a high level of confidence.
Batch Qualification
A lot is accepted only if the mean of the sample is sufficiently far from the lower or upper limit relative to the measured standard deviation. If the spread of the data is too wide, the s-method triggers a rejection even if the average seems acceptable. This ensures that the buyer does not receive a shipment with too many individual pieces that fall below the minimum standard.
Risk Tolerance
Choosing this statistical path depends on the cost of testing and the required level of precision. High-value technical fabrics often use this method to guarantee performance in safety-critical applications.