A container label has one job: to identify the container by the same number after every wash, so what needs testing on site is readability, not code type. QR codes add Reed-Solomon error correction. According to Denso Wave it comes in four levels, and level Q or H is suggested for factory environments where dirt is expected. That is how a partly damaged QR can still be read.
- Give each container a fixed number and encode only that number; everything else stays in the system, because whatever is embedded in the code cannot be updated.
- Print the number in readable form beneath the code, so it can be keyed in by hand when the code will not read.
- Scan clean, soiled, washed and worn containers with a phone and a handheld reader; record the result together with device and lighting.
- Put the label on a sheltered face of the body, using material and adhesive that survive the wash line.
Add time, location, user and action type to each scan record; duplicate codes and mismatches show up in that record. A pilot result holds only for the label and device tested.
