What is the Difference Between TDS and COA?
Document Roles
The Technical Data Sheet (TDS) is used to discuss target specifications and applicable methods; the Certificate of Analysis (COA) should be verified for batch number, actual producing factory, listed parameters, and test results. If the production date is not stated, it shall be treated as unknown and verified with the issuer. Typical values must not be taken as guaranteed values for every batch.
Verification Sequence
First verify the certificate issuer and batch number, then check the corresponding cargo marks, packaging, and quantity, and finally compare each item item-by-item against the contract specifications. The test date and issue date shall not be inferred as the production date; parameters not listed shall not be deemed conforming. Data from consecutive batches may reveal fluctuations, but still cannot replace a complete customer qualification.