3 ms·

Absolutely. You'll likely need to use a thermocouple though. Something like this http://www.adafruit.com/products/270 http://www.adafruit.com/products/270 and

Absolutely. You'll likely need to use a thermocouple though. Something like this http://www.adafruit.com/products/270 http://www.adafruit.com/products/270 and this http://www.adafruit.com/products/269 http://www.adafruit.com/products/269 play nicely together. Hook the sensor up to the Arduino, have it print out the values when you want them, go to town. The only draw back is that you'll have to run the thermocouple into the refrigerator and seal it. Most electronics are rated to about -40C, so unfortunately you won't have a nice wireless solution.

michaelcampbell 14y ago
Serious question: Why are most electronics rated to -40? (Note: -40C and -40F are the same... =) Anyway, is it due to thermal contraction/expansion at that temp vs. "room temperature" that they spend at least some of their life at?
- mercuryrising 14y ago
  Compared to the temperature changes that the wafers go through when processing (>800C for annealing, lower temperatures when we start putting more materials on the silicon's surface), the silicon itself will likely be fine from the temperature shifts. It will be more brittle, but the amount of wafer in a semiconductor is so small it likely won't crack. We have to worry a little bit about the plastic expanding differently than the wafer, but the wafers are so teeny it likely won't be an issue. Electronics usually work better when they get colder, just look at the people who overclock with liquid nitrogen, although the silicon inside is still providing a heat source, preventing the silicon from getting to 77K. Back to the answer though, I don't know for sure. A little bit of googling brought me here http://www.electronics-cooling.com/2004/02/the-temperature-ratings-of-electronic-parts/ http://www.electronics-cooling.com/2004/02/the-temperature-r... where they said 'hot electrons' are a cause of degradation. When electronics are running under normal conditions, there's lots of bumping into each other. The kinetic energy of the electrons never gets too high, as any electrons that gain energy will 'collide' with another electron, transferring some of the energy. When it gets sufficiently cold though, the electrons are not moving around as much. There's less chance of a collision, and more chance they electrons will gain enough energy to quantum mechanically tunnel into the insulator. This is bad, as we now have charges that are stored in our gate and they cannot be removed. Interestingly, this is the same principle that allows us to build flash memory. There is a 'floating gate' that stores charge for an extended period of time (hopefully indefinitely if you don't want to lose your data). By applying a large voltage to the gate, we can charge or uncharge the gate, allowing us to write 1's and 0's. But that's just my theory, I couldn't find a clear answer in my bit of googling. The business reason would likely be that they can rate it in that range that most people are perfectly acceptable with, they don't have to test it outside those ranges, and they can make more money off of the parts that they sell outside of that range as there is less demand for them.

michaelcampbell 14y ago

Serious question: Why are most electronics rated to -40? (Note: -40C and -40F are the same... =) Anyway, is it due to thermal contraction/expansion at that temp vs. "room temperature" that they spend at least some of their life at?

mercuryrising 14y ago
Compared to the temperature changes that the wafers go through when processing (>800C for annealing, lower temperatures when we start putting more materials on the silicon's surface), the silicon itself will likely be fine from the temperature shifts. It will be more brittle, but the amount of wafer in a semiconductor is so small it likely won't crack. We have to worry a little bit about the plastic expanding differently than the wafer, but the wafers are so teeny it likely won't be an issue. Electronics usually work better when they get colder, just look at the people who overclock with liquid nitrogen, although the silicon inside is still providing a heat source, preventing the silicon from getting to 77K. Back to the answer though, I don't know for sure. A little bit of googling brought me here http://www.electronics-cooling.com/2004/02/the-temperature-ratings-of-electronic-parts/ http://www.electronics-cooling.com/2004/02/the-temperature-r... where they said 'hot electrons' are a cause of degradation. When electronics are running under normal conditions, there's lots of bumping into each other. The kinetic energy of the electrons never gets too high, as any electrons that gain energy will 'collide' with another electron, transferring some of the energy. When it gets sufficiently cold though, the electrons are not moving around as much. There's less chance of a collision, and more chance they electrons will gain enough energy to quantum mechanically tunnel into the insulator. This is bad, as we now have charges that are stored in our gate and they cannot be removed. Interestingly, this is the same principle that allows us to build flash memory. There is a 'floating gate' that stores charge for an extended period of time (hopefully indefinitely if you don't want to lose your data). By applying a large voltage to the gate, we can charge or uncharge the gate, allowing us to write 1's and 0's. But that's just my theory, I couldn't find a clear answer in my bit of googling. The business reason would likely be that they can rate it in that range that most people are perfectly acceptable with, they don't have to test it outside those ranges, and they can make more money off of the parts that they sell outside of that range as there is less demand for them.