To blow or not to blow?

Everyone knows that tea cools faster if it blows on it. I also became interested in the effectiveness of such a procedure in numbers. Therefore, I was an experiment, the essence of which is depicted in the picture below. If results are interesting to you - welcome under kat.



The essence of the experiment is simple as a door. In two identical glasses the same amount of water is poured, equal to the temperature. Two identical sensors (DS18B20) transmit data to a computer, where the temperature is plotted as graphs. Blowing one of the glasses - we fix the changes. Below is the “calibration” procedure, the essence of which is to get the relative difference between the readings of two sensors that are in the same conditions.


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The graph changes when cooling the glass with heated water to room temperature:



In this experiment, we are more interested in relative accuracy than absolute. And, as can be seen from the graph below, the difference in the readings of two sensors is less than a degree, in the temperature range of the experiment.



The experiment itself. On the glasses you can see the labels of the water level. We start blowing after about 5 minutes so that the experiment is cleaner.





Absolute Graphics:



And relative temperatures:



Conclusions: The results of the experiment speak for themselves. If you want to cool the tea faster, you should definitely blow.