CQA staff cut samples from a set number of rolls, often one per lot or per set area, and send them to an independent lab for properties such as thickness, density, tensile, OIT and carbon black. Results are compared with spec values, usually MARVs or minimums, before the rolls are installed. Failing rolls are rejected and testing is widened across the lot.
Conformance testing on lot 4 failed thickness, so tag those rolls and keep them off the slope.
Pull conformance samples when the rolls arrive, before they are spread around the site, so a failing lot can still be sent back whole.
Also heard as
- conformance sampling
- acceptance testing
Related terms
MARV
Minimum average roll value: the lowest average test result a product guarantees for any roll it ships.
CQA
Construction quality assurance: independent monitoring and testing that a geosynthetic system was built as designed.
Asperity height
Height of the raised texture on a textured geomembrane, measured from the core of the sheet.
OIT
Oxidative induction time: a measure of how much antioxidant protection remains in a polyolefin geosynthetic.