Today I had a question about the use of temperature loggers with the transport of fresh basil. The problem was in regards to the receiver rejecting shipments because the basil was out of the required temperature range (8° to 14°C). The temperature logger needed to either demonstrate that the basil was within range, or try to identify when and how often it was out of range.
This is a common problem for anyone shipping temperature sensitive goods. When you are shipping directly to the customer, they are in control of accepting and rejecting the shipment. If they reject it, then you have a battle with either the customer or the transport company.
So how can you demonstrate that the goods are fit for delivery, or if they aren’t, that the transport company has failed to provide the required service?
The answer is obvious “with a temperature logger” and there are other blogs explaining the benefits of temperature loggers when transporting anything.
The next big question is then “which temperature logger?” and it is this question that I want to look at in more detail.
We have a wide range of loggers and often there is no practical difference between them for many customers. In this case, however, there are two questions that quickly point to the “best” solution.
There are a couple of possible answers for this, and it will point you to a specific brand or model of temperature logger.
The reality is that the Thermochron and LogTag loggers are all reasonably small and can be placed almost anywhere.
The Thermochron is significantly smaller than the other two, and since it is stainless steel it will be water resistant. The lack of indicators, however, is likely to rule it out for this application.
Some LogTags have the option for an external probe. This means that the logger can sit on the outside of the box and the probe go through a hole and be placed where ever it is required. Probes are water proof and can be placed anywhere.
One simple answer is “where the customer will test it”.
But since there is likely to be a significant variation in temperature it is worthwhile actually doing a single run with a number of loggers in the one box. This will provide an insight into the temperature variation within the box. If there isn’t much of a variation then the choice as to where to place it is immaterial, and it can go in the most convenient location.
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.
