He’s written a nice Instructable on a Temperature Data Logger that he has built and thankfully ... opened in spreadsheet software to make a graph showing temperature change over time.

Thermal data loggers and temperature monitors both rely heavily on thermocouple sensory inputs to assess the component’s thermal values or a sample under test. They consist of wired metal junctions ...

Temperature ... The T-TEC data loggers record over time and store logs in a large internal memory, which can then be downloaded to a PC. Data can be presented as a graph, or exported to a ...