Extreme low temperature control
Liquid nitrogen level indicator
Laboratories, healthcare institutions, cryo- and biobanks use liquid nitrogen (LN2) to store samples: in dewar containers. Biological samples such as oocytes, embryonic tissues, cells, sperm, blood, etc. can be stored and transported in vacuum flasks, the temperature being held constant at -196 oC by slow boiling of the LN2.
Risks from the loss of biological samples for significant, irreversible consequences for patients and the possible legal liability of laboratories.
Thus, continuous monitoring of the temperature and liquid nitrogen levels of cryogenic storage units is extremely important. The temperature should never exceed the limit of -130 ° C. Depending on the size and design, the holding time of vacuum flasks ranges from a few hours to a few weeks.
There are signaling and alarm systems for monitoring the temperature of a sample stored in a dewar, but they are not suitable for monitoring a large number of containers.
The IoT system we have developed works according to the following scheme.
Advantages, How It Works
1./ A K-type sensor (thermocouple) placed in the container converts the analog signal of the voltage change due to the temperature change (the change of the ambient temperature of the sample placed in the dewar) into the digital signal of the connected digitizer.
Type K thermocouples usually work in most applications as they are nickel based and exhibit good corrosion resistance. It is the most common sensor calibration type providing the widest operating temperature range.
2./ The digitized signal is suitable for wireless transmission.
3. / A multi-channel signal processor continuously monitors the temperature change in the tanks, sending a notification about the amount of LN2 in the tanks, allowing the optimization of liquid nitrogen orders.
4. / alarm in case of extremely fast temperature change (in case of dewar vessel cracking and the nitrogen boils extremely fast, which causes the samples to heat up and destroy). It allows for the safe placement of valuable, sometimes irreplaceable samples.
5. / With the PC connected, it allows to retrieve the temperature diagrams of the storage vessels, which can be used to predict the failure.
6. / The security of the system and the storage facilities can be continuously monitored and controlled remotely via the Internet with a mobile application.
7. / the system may be suitable for controlling other devices (due to the wide temperature range of the sensor) than incubators or mechanical refrigerators.