Space too cold for waterproof DS18B20

Hey,

I'm testing an Arduino hooked up to 3 DS18B20 waterproof thermometers and an SD card in a freezer with dry ice. The goal of the project is to send a weather balloon to 100,000 fr where it will experience -50C. On the first test the SD only recorded for 2 minutes even though the Arduino still had power and was on. To troubleshoot, I tested each component (SD reader, battery pack, temperature sensors, and Arduino) separately. Only when the temperature sensors were in the freezer did the the SD stop recording. I tested the Arduino with only the SD reader in the freezer and it recorded the entire time.

The wires to the temperature are pretty long, I'm wondering if the cold effects the resistance enough that they are unable to draw enough power.

Does anyone have guidance on how to additionally troubleshoot this issue? Why would only the temperature sensors cause the SD to stop writing?

Thanks in advance for any help.

Use code tags and attache the code. I might depend on the code You did not supply….. No information about most of the stuff You use. How do You think we will know?

conteph: I'm testing an Arduino hooked up to 3 DS18B20 waterproof thermometers and an SD card in a freezer with dry ice. The goal of the project is to send a weather balloon to 100,000 fr where it will experience -50C.

I take it you are aware the sensor is only accurate down to minus 10 degrees C..??

This one goes down to -196C

https://www.digikey.com/product-detail/en/te-connectivity-measurement-specialties/SB0873/223-1651-ND/5277377

Another issue you will have to solve is the ATMEGA is good to -40C. Keep in mind when go from warm to cold to warm again you will have condensation issues. This sort of thing is very challenging.

conteph: Only when the temperature sensors were in the freezer did the the SD stop recording. I tested the Arduino with only the SD reader in the freezer and it recorded the entire time.

And what exactly do you mean by 'the SD stop recording' ?

The Arduino stops running as in a hange up of some sort ?

The Arduino is still running but nothing is written to SD ?

The Arduino is running and writing to SD but there is no entry for the temperature ?

The Arduino is running and writing to SD but the recorded temperature is wrong ?

I used a DS18B20 in a high altitude project, it reported down to -30c, its cold when it gets dark …

The wires to the temperature are pretty long, I'm wondering if the cold affects the resistance enough that they are unable to draw enough power.

Resistance of metals falls with falling temperature, it does not increase. In any case, you can test this yourself, put some of the cable in the freezer with the ends shorted and measure the resistance as it cools.

I don't know the answer to your question but I would suspect that the sensor is not rated for the temperatures you want to measure. Check the data sheet, it should be on there. Also, if there is any other electronics co-located with the sensor check its data sheet for operating temperature range.