Link Waveforms and Images to the Correct PCB Test Attempt

A waveform named capture.png or a photograph copied into a shared folder is weak evidence when several boards were tested that day. The file may be intact yet belong to another unit, another attempt, or another configuration. Define the link between each attachment and the test record that gives it meaning.

NIST’s message-digest glossary describes using a cryptographic checksum to detect file changes. Such a check can support integrity verification, but it does not establish which board produced the file or whether the capture method was valid.

Create an attachment manifest

Assign an attachment identifier and connect it to the unit, attempt, and test step. Record the original capture time, producing instrument or application, file type, and relevant setup reference. Include a short description of the physical observation, such as which connector, board side, or measurement node the attachment represents.

Keep the original file when creating annotated or compressed versions. Identify each derivative and its relationship to the original. A cropped image may remove a scale marker or orientation cue; an exported waveform may omit metadata available in the native record.

Separate three review questions

Do not let a matching checksum stand in for all three answers. Conversely, an expected checksum mismatch should trigger investigation of the transfer or transformation history, not an immediate conclusion that the underlying board failed.

Check retrieval as well as capture

1. Save attachments using unique identities that avoid accidental overwrite.
2. Complete the result-to-attachment association.
3. Retrieve the result through the normal review interface.
4. Open the associated file and verify its context.
5. Check that required attachments remain available after archival or migration.

Exercise interruption cases, including a result saved before its attachment upload completes. The review interface should distinguish a pending file from a missing file and a missing file from an intentionally omitted attachment. Do not display a previous attachment as a placeholder that could be mistaken for current evidence.

Define retention and access according to the production agreement and applicable internal requirements. Avoid placing sensitive customer identifiers in public filenames or uncontrolled sharing locations. Close each investigation with the original evidence preserved and any explanatory annotations clearly identified. The result-storage guide addresses how attachment completion fits into the broader station workflow.