Wild Temp Sensor spikes that don't seem to have a cause

My person analysis

How the temp sensor works
Every 200ms, the temperature sensor will record its current temperature. Every 1600ms, the sensor will sum the 8 records and then divide it by 8.

 

How the strange number happen
When CO2(gas) is cold enough and turn to liquid/solid, a vacuum hole will occupy the CO2 gas's previous position. And the temperature of vacuum hole (0K) will be recorded by the sensor.

Result
Assume the true surrounding temperature is -78.3, and the vacuum hole(-459.67°F) occurs once in the 1600ms.
The average temperature acquired by sensor will be (-78.3*7 + -459.67)/8=-126°F

Like the following photo

If twice, the number will be -173.6°F, like this 

@R9MX4  Wow, that makes perfect sense, if almost impossible to figure out without knowing the 8 averages per 1.6 seconds.  I'm not sure what the best choice to avoid the problem is offhand though.  It certainly causes some rather aggravating results when trying to freeze store CO2, as the transition window from gas to solid is incredibly fast for how small the change window is in temperatures.

Edited May 29, 2018 by WanderingKid