Logger sampling interval simulator

How the calculation works

1. 01A reference 24-hour cold-room trace is generated at 1-minute resolution, including compressor cycling, two defrost cycles and a goods-in door opening.
2. 02The logger is simulated by taking every nth minute from that trace, starting at 00:00 — exactly what a logger set to an n-minute interval does.
3. 03An excursion is any reading outside the limits; the duration a reviewer would report is the number of such readings multiplied by the interval.
4. 04The true excursion is measured on the 1-minute trace, so recorded and actual can be compared directly.

Limitations

• The trace is a realistic demonstration, not a recording of a real facility, and not a thermal model of any particular room.
• Sampling starts on the hour. A logger started at a different offset would catch a different slice — which is itself the point: what a slow logger sees is partly luck.
• It shows detection, not compliance. Whether an excursion matters is decided by the product's stability data.

Frequently asked questions

What sampling interval should I use for temperature mapping?

One to five minutes is the usual recommendation, because it resolves door openings, defrost cycles and compressor cycling. This simulator shows why: at 30 minutes, a 17-minute excursion that peaked at 9.6 °C leaves no trace in the data at all.

Can a logger miss a temperature excursion completely?

Yes. If the excursion begins and ends between two readings, nothing in the dataset records it. The study then looks clean, and the excursion cannot be investigated, reported or learned from.

Why does a slower logger show a lower maximum?

It only ever sees the moments it sampled. A peak that happens between readings is not averaged in or smoothed — it is simply absent, so the recorded maximum understates the real worst case.

Does a shorter interval mean too much data?

Rarely a real constraint. A modern logger stores weeks at one-minute resolution, and 1,440 readings a day is trivial to analyse. The storage saving from a slow interval is worth far less than the evidence it costs you.