5 ms·

Related ... the last time I was in the market for a chest freezer (a "deep freeze") I wanted one that showed a log of temperature over time ... This, essential

by rsync 6y ago

Related ... the last time I was in the market for a chest freezer (a "deep freeze") I wanted one that showed a log of temperature over time ... This, essentially, does not exist. It appears that there are laboratory freezers that support this (very simple) feature, but they are relatively small and very expensive. A better way to go is an electricity monitor on the plug, where you track electrical power over time and assume (reasonably) that full electrical power implies full temperature control. Still ... a simple log of temperature over time (without resorting to weird solutions with raspis dangling temp wires into the freezer ...) would be a very nice feature and I'm disappointed that it doesn't exist ...

oh_sigh 6y ago
You could just freeze a cup of water, and then stick a penny in top of it. If you ever come back to find your penny embedded or at the bottom of the cup, you know your freezer thawed out at some point
- jandrese 6y ago
  Just make sure to cover the cup so the ice doesn't sublimate away.
badRNG 6y ago
> without resorting to weird solutions with raspis dangling temp wires into the freezer ... Well, I had a solution up till that line. There's gotta be an elegant way to set something like that up on top of the fridge out of sight with clean cable management into the freezer.
- ghaff 6y ago
  If you're going to bother--especially with a chest freezer--you probably want a number of temperature probes anyway. Just because there's been some thawing at the top/front doesn't mean that everything has thawed.
kevindong 6y ago
Such data might be interesting to look at, but as long as the freezer does its job (aka keep everything stored within it fully frozen), what's the point in having that data?
- ponker 6y ago
  So you know when that assumption is false.
- nickpeterson 6y ago
  Keep in mind that while They’re not overly expensive, it’s pretty easy to pack a few thousand dollars worth of food in a chest freezer. Might be worth testing it...
- rsync 6y ago
  "... what's the point in having that data?" In normal, day to day life, I think it would have little value. The use-case I am envisioning here is: you have a high value store of frozen items (meat, etc.) and you leave your home for 20 or 30 days ... When you get back, the freezer is running nicely and everything is frozen and things look great - but what if there were a 3 or 4 or 5 day power outage in the middle of your trip that thawed things out just enough to spoil ? Or what if there were one or more power outages (or brownouts) that you were aware of that were not, in fact, long enough to ruin your stored food ... but how would you be sure ? If you had a time view of freezer temps you could make those determinations easily.
  - tzs 6y ago
    If you can live with just minimum, current, and maximum temperature instead of a detailed log, this works well [1]. [1] https://www.amazon.com/gp/product/B004QJVU78/ https://www.amazon.com/gp/product/B004QJVU78/
  - Simon_says 6y ago
    This is all kind of overkill. Just put a penny on the surface of a cup of ice in the freezer.
dpeck 6y ago
Freeze cup of water with some red food coloring in it. Turn upside down. If you ever come back to a freezer that looks like it’s covered in frozen blood you’ll know.
- teej 6y ago
  I always heard this as an upright cup of frozen water with a penny on top. If you come home and the penny is inside the ice you know the freezer went out.
  - miked85 6y ago
    Seems a bit easier than covering your freezer in red food coloring
  - lxmorj 6y ago
    That is a much cleaner method
  - thaumasiotes 6y ago
    I think it bears mentioning here that you need to choose a cup that can survive the expansion of its contents. Or in other words, not a glass cup.
willis936 6y ago
I personally think the raspi approach is fine. If you want off the shelf, there are temperature and humidity loggers that are cheap. They’re typically wifi based and host a webpage. Some even come with probes so you don’t need to have the antenna inside a Faraday cage.
jonathankoren 6y ago
I had this very discussion on Twitter a few days ago, wrt "smart" refrigerators. The one thing that would be legitimately useful would be a batter back real time clock and thermometer, to alert you when the power went out, and what to throw away. I'd be shocked if this feature exists on any refrigerator. Not because it's difficult (It's not. Just monitor the temperature and print a stock FDA guidance), but because it's not what a product manager actually thinks of. Instead we get cameras inside, weather, Alexa integration, Google photos, just... bullshit features. Nothing that that anyone really needs.
golem14 6y ago
that's a great DIY project for an esp8266 and a temperature probe. Could even be a kickstarter. Everyone with kids worries about them leaving a fridge or freezer open.
odonnellryan 6y ago
There are $10 battery operated thermometers on Amazon that give you a min and max recorded temp. That is all you need for safety.
01100011 6y ago
You can pick up a cheap temperature logger: http://www.elitechlog.com/rc-5usb-temperature-data-logger/ http://www.elitechlog.com/rc-5usb-temperature-data-logger/ My apartment has what appears to be the worst refrigerator ever made. It's a cheap GE unit with a single temperature control. You have to choose between freezer burnt steaks or frozen milk. I used that temp logger to confirm what was going on.
technofiend 6y ago
My wife was convinced the refrigerator was failing so I bought a few sensor tags from wirelesstag.net [1] just to be sure. You can certainly build your own using off-the-shelf IOT devices, but for ~$35 you can have a device that senses temperature, humidity, light levels,and runs for several months off an easily replaced cr2032. Although to be fair you must buy a base sensor station for $39 along with the first tag. Having said that, it definitely gives me peace of mind knowing that my fridge isn't going out and that I haven't left the door open, either. Next on the agenda is using my smart home controller to adjust cooling temperature on my window unit based on ambient temperature in my bedroom. https://store.wirelesstag.net/products/wireless-tag-als https://store.wirelesstag.net/products/wireless-tag-als
- deleted 6y ago
  [deleted]
- gruez 6y ago
  I looked at the product page for the wireless sensor and I saw this: >No subscription fee of any kind for life; no monthly or annual fee to use cloud service and no cloud storage fee for data collected by sensor tags. >High anonymity: only your account email address and tag manager IP address is collected That sounds... slightly disturbing. It suggests the tags sends all the data to the manufacturer's server. That's bad from a privacy and reliability (eg. company goes bust in a few years) perspective.
  - technofiend 6y ago
    Yes. Your data is relayed to them.
earth_walker 6y ago
This is going to sound a little overkill, but I do have some experience in this area, and this is the right forum for it so... Digital thermometers for freezers are relatively cheap (if you don't need them NIST traceable, anyway) and easy to get from any number of laboratory catalogues (See, for example, Thermo-Fisher or Cole-Parmer). You can even purchase a chart recorder that'll sit on top of your freezer if you want! If you're just concerned about brown-outs and fluctuations, you can go with a cheap, magnetic max/min like the Cole-Parmer Jumbo (fine for consumer freezers) that sits on the front of the unit. You need to thread the wires through the freezer door, though, unless you're lucky enough to have a port on the side or back. If you want a boatload of data you can go all out with a digital datalogger with a Type T thermocouple (Type T will even work reliably on -80C ULT freezers). I highly recommend Onset Hobos for reliability. There are also bluetooth and wifi models that allow you to get the data to your devices. As an aside, stay away from Oakton as a brand if you're doing anything mission critical. If you don't want the wires sticking through the doors, I've had good success mapping temps with the Thermochron ibuttons - they are the size of a watch battery and some models work down to -40C. If you set the frequency low (e.g. every hour) they'll log data for months before you need to pull them. You can also get waterproof enclosures for them and throw them in the dishwasher for fun!

by rsync 6y ago

oh_sigh 6y ago

You could just freeze a cup of water, and then stick a penny in top of it. If you ever come back to find your penny embedded or at the bottom of the cup, you know your freezer thawed out at some point

jandrese 6y ago
Just make sure to cover the cup so the ice doesn't sublimate away.

badRNG 6y ago

> without resorting to weird solutions with raspis dangling temp wires into the freezer ... Well, I had a solution up till that line. There's gotta be an elegant way to set something like that up on top of the fridge out of sight with clean cable management into the freezer.

ghaff 6y ago
If you're going to bother--especially with a chest freezer--you probably want a number of temperature probes anyway. Just because there's been some thawing at the top/front doesn't mean that everything has thawed.

kevindong 6y ago

Such data might be interesting to look at, but as long as the freezer does its job (aka keep everything stored within it fully frozen), what's the point in having that data?

ponker 6y ago
So you know when that assumption is false.
nickpeterson 6y ago
Keep in mind that while They’re not overly expensive, it’s pretty easy to pack a few thousand dollars worth of food in a chest freezer. Might be worth testing it...
rsync 6y ago
"... what's the point in having that data?" In normal, day to day life, I think it would have little value. The use-case I am envisioning here is: you have a high value store of frozen items (meat, etc.) and you leave your home for 20 or 30 days ... When you get back, the freezer is running nicely and everything is frozen and things look great - but what if there were a 3 or 4 or 5 day power outage in the middle of your trip that thawed things out just enough to spoil ? Or what if there were one or more power outages (or brownouts) that you were aware of that were not, in fact, long enough to ruin your stored food ... but how would you be sure ? If you had a time view of freezer temps you could make those determinations easily.
- tzs 6y ago
  If you can live with just minimum, current, and maximum temperature instead of a detailed log, this works well [1]. [1] https://www.amazon.com/gp/product/B004QJVU78/ https://www.amazon.com/gp/product/B004QJVU78/
- Simon_says 6y ago
  This is all kind of overkill. Just put a penny on the surface of a cup of ice in the freezer.

dpeck 6y ago

Freeze cup of water with some red food coloring in it. Turn upside down. If you ever come back to a freezer that looks like it’s covered in frozen blood you’ll know.

teej 6y ago
I always heard this as an upright cup of frozen water with a penny on top. If you come home and the penny is inside the ice you know the freezer went out.
- miked85 6y ago
  Seems a bit easier than covering your freezer in red food coloring
- lxmorj 6y ago
  That is a much cleaner method
- thaumasiotes 6y ago
  I think it bears mentioning here that you need to choose a cup that can survive the expansion of its contents. Or in other words, not a glass cup.

willis936 6y ago

I personally think the raspi approach is fine. If you want off the shelf, there are temperature and humidity loggers that are cheap. They’re typically wifi based and host a webpage. Some even come with probes so you don’t need to have the antenna inside a Faraday cage.

jonathankoren 6y ago

I had this very discussion on Twitter a few days ago, wrt "smart" refrigerators. The one thing that would be legitimately useful would be a batter back real time clock and thermometer, to alert you when the power went out, and what to throw away. I'd be shocked if this feature exists on any refrigerator. Not because it's difficult (It's not. Just monitor the temperature and print a stock FDA guidance), but because it's not what a product manager actually thinks of. Instead we get cameras inside, weather, Alexa integration, Google photos, just... bullshit features. Nothing that that anyone really needs.

golem14 6y ago

that's a great DIY project for an esp8266 and a temperature probe. Could even be a kickstarter. Everyone with kids worries about them leaving a fridge or freezer open.

odonnellryan 6y ago

There are $10 battery operated thermometers on Amazon that give you a min and max recorded temp. That is all you need for safety.

01100011 6y ago

You can pick up a cheap temperature logger: http://www.elitechlog.com/rc-5usb-temperature-data-logger/ http://www.elitechlog.com/rc-5usb-temperature-data-logger/ My apartment has what appears to be the worst refrigerator ever made. It's a cheap GE unit with a single temperature control. You have to choose between freezer burnt steaks or frozen milk. I used that temp logger to confirm what was going on.

technofiend 6y ago

My wife was convinced the refrigerator was failing so I bought a few sensor tags from wirelesstag.net [1] just to be sure. You can certainly build your own using off-the-shelf IOT devices, but for ~$35 you can have a device that senses temperature, humidity, light levels,and runs for several months off an easily replaced cr2032. Although to be fair you must buy a base sensor station for $39 along with the first tag. Having said that, it definitely gives me peace of mind knowing that my fridge isn't going out and that I haven't left the door open, either. Next on the agenda is using my smart home controller to adjust cooling temperature on my window unit based on ambient temperature in my bedroom. https://store.wirelesstag.net/products/wireless-tag-als https://store.wirelesstag.net/products/wireless-tag-als

deleted 6y ago
[deleted]
gruez 6y ago
I looked at the product page for the wireless sensor and I saw this: >No subscription fee of any kind for life; no monthly or annual fee to use cloud service and no cloud storage fee for data collected by sensor tags. >High anonymity: only your account email address and tag manager IP address is collected That sounds... slightly disturbing. It suggests the tags sends all the data to the manufacturer's server. That's bad from a privacy and reliability (eg. company goes bust in a few years) perspective.
- technofiend 6y ago
  Yes. Your data is relayed to them.

earth_walker 6y ago

This is going to sound a little overkill, but I do have some experience in this area, and this is the right forum for it so... Digital thermometers for freezers are relatively cheap (if you don't need them NIST traceable, anyway) and easy to get from any number of laboratory catalogues (See, for example, Thermo-Fisher or Cole-Parmer). You can even purchase a chart recorder that'll sit on top of your freezer if you want! If you're just concerned about brown-outs and fluctuations, you can go with a cheap, magnetic max/min like the Cole-Parmer Jumbo (fine for consumer freezers) that sits on the front of the unit. You need to thread the wires through the freezer door, though, unless you're lucky enough to have a port on the side or back. If you want a boatload of data you can go all out with a digital datalogger with a Type T thermocouple (Type T will even work reliably on -80C ULT freezers). I highly recommend Onset Hobos for reliability. There are also bluetooth and wifi models that allow you to get the data to your devices. As an aside, stay away from Oakton as a brand if you're doing anything mission critical. If you don't want the wires sticking through the doors, I've had good success mapping temps with the Thermochron ibuttons - they are the size of a watch battery and some models work down to -40C. If you set the frequency low (e.g. every hour) they'll log data for months before you need to pull them. You can also get waterproof enclosures for them and throw them in the dishwasher for fun!