Ch-2 Keeping a check on temperature deviations

Continuing from our previous blog post..

In our previous study on fridge behaviour we highlighted the concern that maybe the twice a day temperature checks are fallible. We also posted other questions that begged answers.

Fridge goes N misses check.png

We did extended logging in a live environment with multiple fridges, chillers, walk-ins, cafe. We deployed the latest Internet of Things technology in an NZ first trial to see what was going on. We were able to position accurate sensors in each Cooler. No thermometers, no wiring. Just sensors beaming out readings from inside the fridge/cooler. We collected all these readings in a central mini gateway. Every six minutes. So whether door open or not we could “see” what was happening.

And of course that meant we could verify times and activity

The major point made in the previous blog post was that two checks a day does not reliably cover the wider picture. Those checks are just valid for a small point in time.

Commercial Fridge Sensor

Commercial Fridge Sensor

So first impressions were interesting. The accompanying Fridge graph fully emphasises the disconnect between Thermometer checks and the bigger picture. In this case a fridge temperature shot up to 27.5 degC and stayed high for over three hours. This happened at 03.30 am and came back to normal at 06.00am.

Now this did not happen on its own. It will have likely happened because a staff nurse opened the fridge, took something out but then failed to close door properly. Sound unlikely? Not really. This is the most common issue from our study. If a door seal is not made and left ajar just 10mm then in the space of thirty minutes or so, temperature goes North.

At 04.59am, Nurse probably opens fridge again but this time the door gets shut properly. Temperature returns slowly back to normal.

Now envisage where the twice daily checks were made. We would suggest nowhere near that time of night. What damage has quietly been done? But at least the occurrence is now there to be seen.

Note: All sample logs, unless otherwise stated, were taken from routine tests prior to Mimocool alerts being actioned

Message from John Williams CEO,

If you want to have a look see at what your fridges and cold storage are reporting 24/7, then we can loan you a no obligation test kit. See contact form and check option ‘Test Kit’ and we will arrange delivery details with you

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