How to compare two loggers in one container

If two loggers diverge, verify the same run, serial numbers, container identity and interval. A difference alone proves no fault.

Finding when they diverge

Align records and note clock settings. Track differences through the run; verify time basis before linking them to events.

Keeping time fields distinct

Record time zone, device clock and download time separately. A clock mismatch can shift traces. Keep original files and document alignment.

Recording position

Record each logger's position, mounting and intended product area. Verify choices against the model manual and quality plan.

Which record goes in the report. Use the preselected product area. If retaining both devices, report identities and positions. Interpretation follows product specifications and quality process.

A difference between traces may show that the measurement points experienced different conditions; by itself it does not establish device failure or product condition.

Monthly review

Record when the largest difference occurred and both readings. Note identity and time verification; do not pool unverified pairs.

Role of the second device. Retain or remove the second device per measurement plan. Record date, reason and remaining device identity and position. Follow authorized quality process.