Temperature monitoring is very interesting to me and also part of my day-job for testing refinery and power generation equipment performance. Most test thermocouples or RTD's are special tolerance with calibration records at a select temperatures. Also, most test instruments are bought for a single project and never touched again.
I keep a 2-channel data logger on my fermentation chamber (2-relay controller) with type-K thermocouples - example graph below. I usually log data every 3 minutes.