Down fridge full of beer

Using Dormitory type refrigerators to store vaccines

An NIST study in 2009 determined that dormitory type refrigerators are completely inadequate for vaccine storage. The study which used 19 data loggers to record temperature in these small refrigerators concluded that: “ From these results, it is clear that the dormitory-style refrigerator can not be relied on to maintain vaccine storage temperatures, regardless of the packing density or storage containers used. The dormitory-style refrigerator’s performance was consistently unacceptable, regardless of vaccine storage location within the refrigerator”.

The study which can be seen in its entirety here proved conclusively that although there were some conditions where they might maintain the proper storage temperature for brief periods of time they were not adequate to store vaccines. Any changes made by clinic personal affecting the vaccine locations inside the refrigerator, placement of temperature recording devices, or the use of water bottles were not effective in protecting vaccines that had to be maintained at between 2°C and 8°C.

TV2 showing warehouse fridge/freezer conditions and oven temps

A high temperature data logger

Many industries need to monitor heaters’ or ovens’ temperature over time. Most companies employ high temperature data loggers and/or temperature chart recorders since even small temperature changes, if unnoticed, can cause serious problems. Installing and operating a high temperature data logger (tips) Installation and set-up may require no more than an hour from the moment you take a high temperature data logger out of its box to the
moment it becomes operational. This largely depends on make and model being used. Some data loggers require programming which can require a
great deal of effort especially if you must learn how the software works.

Here are a few things you should keep in mind during the purchase and the installation:

(1) A high temperature data logger will not display the collected information at the site but will need a PC to view the data;
(2) If you chose a temperature chart recorder, you will be able to view the collected information at the site but will have to spend some time changing the chart and pen periodically;
(3) Make sure that you’ve chosen the right kind of sensors. There are different types of sensors for different temperature levels. For high temperature applications a thermocouple is most often used;
(4) Have the sensors calibrated by a calibration;
(5) Remember to set the proper logging rate, which can vary depending on what process you are monitoring. It will make a large difference if you are logging temperature once every 15 seconds as opposed to once an hour;
(6) Most all data loggers store information digitally where as chart recorders record information in an analog format. Temperature chart recorders – use “paper-and-pencil” to record the temperature and their mechanical mechanisms are subject to wear and tear and will eventually fail and require repair or

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TV2 Products Warranty


The TV2 line of Instruments is warranted by the manufacturer to be free from defects in material and workmanship for a period of twelve months after delivery. In the event of a claim under this warranty, the product or part must be returned to the factory for repair or replacement (shipping prepaid) with a Return Authorization Number. It will be repaired or replaced at the factory’s option without charge to the user. Any freight charges incurred may, at the factory’s option, be passed on to the user.

This warranty does not cover routine calibration or battery replacement. The forgoing warranty and remedy are exclusive and in lieu of all other warranties either expressed or implied.

The manufacturer shall under no circumstances, be liable for consequential or incidental damages resulting from failure or malfunction of its products. The manufacturer makes no warranty for products not manufactured by itself or for any products modified by the buyer or subjected to misuse or neglect.

Rick Kaestner


Large TV2 with one temp/RH sensor readout


Hygrometers are single purpose instruments that measure the amount of water in the air.  They actually measure the relative humidity, which is expressed as a percent of comparing the actual water in the air and the amount of water the air could contain if it was completely saturated. While we can at least try to guess what’s air temperature at the moment even without looking at a thermometer, it is much harder if not impossible to measure humidity without a hygrometer. Keeping a stable humidity level can be just as important as keeping the right temperature. High humidity can damage stored food, medicine, etc… just like high temperature can. The only difference is that without a hygrometer you really have no way of knowing that something’s wrong!

Older mechanical hygrometers show only the present relative humidity.  Some more expensive mechanical hygrometers record the humidity on a piece of paper so that you get an actual printed chart, increasing the hygrometers’ usefulness – chart recorders. But hygrometers alone generally only show the present RH level and, unless we spend all of our time watching the readout, they tell nothing about possible humidity fluctuations. So how do you determine that?  Analog chart recorders or digital data loggers record the RH level over time. They are great improvements over the older mechanical hygrometers.

Newer recording hygrometers can be chart recorders or data loggers. Using chart recorders or data loggers that record humidity you can determine if your stored inventory (i.e. food, medicines, electronic materials) are being stored in the proper environment. And If they have an alarm with them they will alert you if something goes wrong so you can take action.

Example: Consider this situation – your computer room is a subject to frequent humidity changes (due to improper air conditioning, for example). Everything’s all right most of the time but occasionally the humidity sharply rises and falls. If no one is present during these times you will never realize that the environment is changing. This can be a real problem for computers.  Too low humidity can lead to static discharges, and a static discharge can completely destroy a hard drive or microprocessor.

A recording hygrometer such as a chart recorder or data logger will keep a record of what happened but are not able to trigger alarms when a dangerous trend occurs.  For that you need a data viewer such as the TV2, so a text, Email or phone call can alert you if the humidity begins to drop.