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.