It’s tempting to run a quick test to “check” your LogTag logger — maybe by dropping it into an ice slurry or comparing it to the display on your vaccine fridge. But here’s the thing: those methods aren’t reliable, and they can lead you to question a device that’s actually doing its job perfectly.
The ice slurry test is often recommended for checking probe thermometers. It works (sort of) because pure ice and water, under the right conditions, should sit at 0°C. But even then, it’s tricky to get right — the mix needs to be just so, and the thermometer needs to be fully stabilised.
LogTag loggers, on the other hand, aren’t designed for this kind of test. They’re not waterproof, they don’t give instant readings, and they sample at intervals. Even if you seal one in a bag and dunk it in ice, you’re not testing its accuracy — you’re testing its response time and how well it handles being in a plastic pouch surrounded by melting ice.
Comparing your LogTag to the built-in thermometer on your vaccine fridge might seem logical, but it’s not a valid accuracy test. Fridge displays often show the temperature of a single spot — usually near the sensor or the fan — and they can be affected by airflow, surface contact or even how recently the door was opened.
LogTag loggers are designed to give a more representative reading of the overall environment. So if your fridge says 4.2°C and your LogTag says 5.0°C, that doesn’t mean the LogTag is wrong — it means they’re measuring different things, in different ways.
If you want a proper test, here’s what you need to do:
Use a traceable reference device: Something calibrated to a known standard, like a certified thermometer or a lab-grade bath.
Make sure the environment is stable: Give it time to level out before making comparisons.
Wait for the logger to settle: With LogTag, look for at least two or three identical readings in a row.
Sync up the sample rate: If your reference device is faster, consider adjusting your logger’s settings to match.
Your test won’t hold water if:
The temperature’s still changing while you’re trying to measure.
The readings bounce around between samples.
You don’t have a verified reference to compare against.
The only way to properly test the accuracy of a LogTag logger is in a certified calibration lab using a controlled test chamber and a traceable reference standard. These labs follow strict procedures to eliminate variables like temperature drift, latency and environmental interference.
Unless you’ve got access to that kind of setup, the best thing you can do is trust your LogTag. It’s been factory-calibrated to meet strict standards, and it’s built to deliver reliable data in real-world conditions — not just in a bowl of ice or next to a fridge dial.
Latency, when it comes to temperature logging, refers to the delay between a change in temperature and when that change is detected and recorded by the logger. This delay can be due to the sensor’s design, the materials it’s placed in, or the logging interval. While it might sound like a disadvantage, latency can actually serve a useful purpose in certain environments—particularly where short-term temperature spikes are common but not harmful.
For example, in a busy commercial fridge, the temperature may briefly rise every time the door is opened. A logger with high latency won’t immediately react to these short fluctuations, helping to avoid unnecessary alarms or false data indicating a problem when there isn’t one. In these cases, a slight delay in response acts like a filter, focusing attention on real issues—such as prolonged exposure to unsafe temperatures—while ignoring the everyday ups and downs that don’t affect product quality or safety.
Depending on the type of logger you have, connecting your logger to your PC means either:
First Generation LogTags use a separate Reader (sometimes called a dock) for configuration and for downloading recorded data.
The Second Generation loggers only require a USB port or cable. Apart from saving the cost of the Reader, this makes them much better suited for shipping, because the recipient doesn’t need a LogTag Reader to download a report about the shipment’s journey.
