Cold Chain Monitoring Data Gaps: A Diagnostic Evidence Checklist

A line drawn across a blank stretch can get a consignment rejected for a temperature that was never stored. Keep the device file, the platform export and the alarm log apart, and leave every cell those files do not fill blank. This checklist is in the temperature monitoring section. It starts from a gap already copied on the shipment temperature chart review.

A cold chain monitoring data gap, on this page, is a stretch where the record in front of you has no stored reading, no transmitted point, or no alarm entry. Split that stretch into five layers: sampling, storage on the device, transmission, the platform or the export, and notification. Copy only what the file prints. The World Health Organization’s May 2015 supplement defines an electronic data logging monitor as a portable device that measures and stores temperature at predetermined intervals and can create reports through proprietary hardware, software, a desktop application, or a hosted database. Vaisala’s viewLinc product page, read on 11 October 2026, says that system’s devices keep existing data in logger memory during a network or power outage and transmit it once the network connection is restored. It does not fill a blank cell on any other system, and a restored connection is not a temperature.

The tables are the sheet. There is no separate file to download. The cover photograph shows a white logger with a dark screen, a coiled grey cable, and a closed laptop on a steel table. No shipment produced it.

Mark which of the five layers is still open

Table: scroll horizontally if needed to see every column.

Layer	Question for this stretch	What counts as an answer	When the file is silent
Sampling	Did the device take a reading in this stretch?	A stored series at the interval the file prints	Leave blank
Device storage	Is a reading still in device memory?	A download taken from the device itself	Leave blank
Transmission	Did a stored point leave the device?	An upload record that names the same stretch	Leave blank
Platform or export	Does the report show the points that arrived?	The export, the server report, or the printed copy you can open again	Leave blank
Notification	Did an alarm reach a person or a device?	The alarm log entry that prints the channel, the time and the recipient	Leave blank

The glossary definition is the sampling row. An electronic data logging monitor measures and stores temperature at predetermined intervals. Write the interval the file prints. If the file prints no interval, the sampling cell stays blank. Do not invent one.

Table 1 in section 2.2.1 lists a limitation of electronic data logging monitors, and of the fixed vehicle event-logger systems: recording frequency and recording time are tied to the size of the device memory. That limitation is a question for the device file. It does not tell you that this stretch was never sampled. Footnote 1 says some versions have a screen where the result can be read, and that a download can still need more equipment. Footnote 2 says some versions are downloadable and produce graphs and detailed data sheets. A screen you can see is not the download. A graph is not, by itself, the stored series.

Section 2.2.2 covers collection, storage and retrieval of downloaded time and temperature data. In most instances that downloaded data should be kept for at least three years, in a form that can be retrieved: a printed hard copy, or a computer hard drive, tape drive, flash drive or DVD. The supplement says storage in a secure web-based repository can also be acceptable. Keep the file the device produced. The three-year figure is that retention rule for time- and temperature-sensitive pharmaceutical products. Other products follow the retention rule your quality unit names.

The same section says go/no-go results from chemical indicators, chemical time-temperature integrators and electronic temperature indicators are written on the product arrival report. That line is an indicator result. It does not fill a missing series on a logger export.

Vaisala’s viewLinc page says months of data can be retained in data logger memory, depending on the device model and the sample interval. It names no model and no interval on the page read for this checklist. Leave both blank unless the file in front of you prints them. The same page says onboard power and memory preserve existing data during a network or power outage. That sentence is about the viewLinc devices the page describes. A power-outage drill, and the choice of a freezer sensor, belong on remote freezer monitoring. This checklist does not specify either one.

Real-time tracking versus downloadable loggers is where the workflow is chosen. This sheet does not pick a workflow. Memory, range and the other purchasing fields belong on the data logger specification guide. Here the device identity only ties a file to the stretch.

The photograph shows a device in a pack. It shows no temperature and no stored file.

Copy the device file, the platform file and the alarm log

Use one row per field. Write only the text that file prints. A blank platform chart does not prove the device never stored the point. A continuous line on a plot does not prove a reading was taken.

Table: scroll horizontally if needed to see every column.

Field	Device file	Platform or export	Alarm log
Record identity
Time span printed
Interval printed
Readings inside the blank stretch
Cause stated on this file
Where the retrievable copy is kept

If a file sits behind an access control you do not hold, leave that column blank and write the name of the person who can export it. This page does not describe a way around that control.

The viewLinc page says measurement data is saved to a database on the server after transmission, and that reports are delivered by email and saved on the server. An emailed report, on that description, is a copy of what that server held. It is not the device memory. Copy it into the platform column when you have it. Leave the device column blank until you have the device download.

The glossary defines a temperature excursion as exposure outside the range prescribed for storage or transport, and it says the product manufacturer sets those ranges from stability data. Copy a range only when that product file is the document in front of you. Otherwise leave the range off this sheet. This checklist does not decide an excursion, and it does not decide whether product can be used.

The photograph shows a closed computer and a closed folder. It shows no chart and no temperature.

A restored connection does not fill the stretch

The viewLinc page says data is automatically transmitted to the server once the network connection is restored. Read that as a statement about viewLinc. It is not a statement about every logger, and it is not a temperature for the minutes the chart does not show. Write “connection restored” in the cause cell only when the file itself prints that cause. If the file is silent, leave the cause blank.

The same page lists “Gap-free data” as a feature of viewLinc. That label stays with that system. It is not a finding about the file in front of you, and it does not license a line drawn through the blank stretch.

Hand the open layers to support

Pass the three files, and the layers still open, to the person who supports the monitoring system your site already uses. Quality holds any decision about the product. This page has no release step.

Table: scroll horizontally if needed to see every column.

Item you pass on	Where you copy it from	Leave blank when
Device identity	The device, or the file that prints the identity	Nothing prints an identity
Start and end of the blank stretch	The file that prints both times	Either time is missing
Layers still open	Your marks on the five-layer table	The three files have not been compared
Product disposition	Not this sheet	Always. Quality holds disposition

The viewLinc page lists alarm notification by email, SMS, voice calls, lights, sirens and relays to external systems. Those are channels named for that system. Copy the channel, the time and the recipient the alarm log prints. If the log prints none, the notification row stays blank. A missed alarm is not a missed sample.

The photograph shows a beacon on a wall. It shows no alarm log and no recipient.

How this checklist was compiled

The blank tables are a comparison sheet for documents you already hold. They are not a gap investigated by this publication, and the photographs are not records of a consignment. The device definition, the memory limitation, the download notes, the three-year retention of downloaded data, the arrival-report line for indicator results, and the definition of a temperature excursion come from the WHO supplement dated May 2015. The sections used are the glossary, 2.2.1 with Table 1, and 2.2.2. That supplement is guidance for time- and temperature-sensitive pharmaceutical products. Statements about logger memory, transmission after a restored connection, server storage, emailed reports, alarm channels, and the “Gap-free data” feature come from Vaisala’s viewLinc product page, read on 11 October 2026. Each of those statements is limited to the system that page describes. No logger model, no gap length, and no acceptance temperature is written into the blank cells.