This is a plot of temperatures from three thermometers at my home, one in a heating duct duct, one outside the house, and one on the floor of a room.
Graph of time (x) versus temperature in ° C (y)
Temperatures are gathered by a PC at home, and about every 7 or 8 minutes, the current date and time and temperature for each thermometer is sent to a MySQL database at my website. These are three of the more expensive thermometers you will ever see.The thermometer for outside the house reads higher than my outside reference temperate at Toronto Island, probably because it is hanging just outside a window, too close to the wall of the house.
Gaps can occur by stopping the temperature collection program, as this viewer displays the last 24 hours of data retrieved from the database. Windows update can restart a machine, and I have not set up auto restart for the thermometer program. If the gap is longer than 10 minutes, the code leaves a gap in the graph for that time interval.