T400 Temperature Datalogger Prototype Walkthrough
Pax Instruments Inc is making an open source temperature datalogger. Charles made a great video going over the entire current prototype showing off the tech inside and reasoning behind many of the build and design decisions. The device is using a MCP3424 A/D, it has 18 bits of resolution so your measurements should be nice and accurate. There is also a lot of thermal management that has been done