Ultra-Low Temperature (ULT) Freezer Monitoring with LoRaWAN Network
Cold storage at Ultra Low Temperatures (ULT) is essential for storing precious products. Certain things, such as irreplaceable biological samples as well DNA/RNA, enzymes drugs and reagents and more, need to be kept at a constant temperature between -50℃ to -85℃. This makes ULT freezers especially common in laboratory and hospital environments - and the cost of the contents of a -80℃ ULT freezer can easily exceed hundreds of thousands of dollars. The problem? A temperature shift of even a few degrees can result in some samples being irreparably damaged. Reliability is absolutely paramount.
Even still, due to the complexity of most -80℃ freezers’ cascaded refrigeration system, hardware failures are not uncommon. Compressors and fans will eventually fail over time, evaporators will ice-up and require defrosting, and of course, there is always the possibility of human error. Give a man a door, and he will one day leave it ajar, just ask any wife. Some sort of alarm system is paramount if you have any hope of catching an issue before it becomes, well, an issue.
ULT freezers are commonly fitted with a relay output that is designed to connect directly to a hard-wired system to alert third party security companies in the event of a temperature increase. Assuming the security company notifies you promptly, you may have time to transfer your product before its ruined. Then again, you may not. Clearly, this is far from a perfect solution. By the time you even get the call, you’ll have no idea what the temperature actually is. All you’re told is that something’s not right.
Telemetry2U has derived a robust solution by connecting Dragino’s LTC2-LT temperature sensor to our IoT cloud platform through a private Long-Range Wide Area Network (LoRaWAN).
-80C is a tough environment to monitor as that temperature can quickly degrade many common sensors and cables. ‘Thermocouples’ are commonly used but these are often fragile and very expensive and can be hard to install depending on the probe type.
We’ve found our solution to this problem in the Dragino LTC2-LT. These sensors come fitted with a double-pressed, waterproof RTD temperature sensor with a range of -200℃ to +200℃, with 0.5℃ accuracy; they are perfectly suited for a ULT environment.
Telemetry2U can provide a NATA certificate produced from an accredited laboratory upon request, but users can also apply their own calibration if ever required. You can also set up scheduled audit reports from Telemetry2U which contain all system information, including charts, alerts details, calibration details and more – enough to satisfy any NATA auditor.
Having access to historical data lets you see how well your ULT freezer is performing. Most manufacturers of -80 ULT freezers recommend manual defrosting every 12-months – but if you’d prefer to be even more proactive, you can. The data gathered by your Dragino LTC-LT2 will let you know how your freezer is performing in real time. Many factors can influence performance: how much product the ULT freezer is storing, how many times the door is opened, and more. This means for some labs, defrosting every 12-months is excessive. For others, it’s not enough. Only defrosting when absolutely necessary saves you enormously on time, money, and risk to your precious samples.
Telemetry2U also supply a range of Aluminium temperature buffers that are deigned to use the with the sensors we supply. Read about the the importance of using a temperature buffer in cold storage environments to better represent your samples and help reduce the chances of triggering false alerts, like when a door is opened for a short time.