ULT -80℃ Freezer Probes: Single- or Multiple-Sensor Modules?

March 16, 2021   |   Temperature Monitoring
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The connection between temperature probes and sensors is essential to monitoring lab freezers — but the way this communication occurs can look different. Sometimes a freezer probe will be plugged into a single-sensor module. Alternatively, a freezer probe will be plugged into a multiple-sensor module. But which of these methods is preferable?

As we showcase here, the length of the freezer probe wire plays a critical role in this answer.

How Freezer Probe Wire Length Factors Into the Equation

Most temperature probes for monitoring ULT freezers can be ordered in variable lengths. These probes plug into a module that reads the temperature of the probe and then transmits the temperature data to a computer or device, which then forwards the readings to the cloud where they are stored and analyzed. From a location standpoint, sensor modules can be mounted on the freezer or on the wall behind the freezer.

The access port for the temperature probe is typically on the back of the freezer, near the top of the appliance. If the module is mounted on the wall, the probe must be long enough that the appliance can be pulled away from the wall for servicing, defrosting and other maintenance reasons. Since some modules can support multiple freezer probes, it’s more convenient to have one module monitor multiple lab freezers that are within reasonable probe wire length.

Because freezer probes are available in a variety of sizes, it’s optimal to use one module to monitor multiple lab freezers to save installation and hardware costs — that is, if the monitored freezers are relatively close to one another. 

As a rule of thumb, if freezers are more than 30 feet apart, it probably makes the most sense to use one module for each freezer. Otherwise, you have to worry about stringing the freezer probe a long distance and worry about all the different scenarios that could disturb the probe wire. Constant activity in the lab can disrupt the probe and eventually lead to probe failure, can dismount the connector from the module or pull the probe out of the freezer.

Simply Put, The Answer Is It Depends

When it comes to the question of single- or multiple-sensor modules, the decision should be based on the layout of your lab. If your lab environment is equipped to handle them, multiple-sensor modules are the optimal solution in terms of time and costs — but if it’s a stretch to make it work, it’s better to use one module for each freezer to avoid potentially damaging the probe.

As the provider of lab temperature monitoring systems, CORIS is passionate about helping lab personnel proactively respond to freezer issues, and establish initial lines of defense to maximize the lifespan of their systems. Download a free copy of this eBook to learn more.