Logging temperature meter (ltm) is a ESP8266 based temperature measurement and logging device.
Above is the prototype, but for this test a small thin film NTC thermistor was attached to the existing engine coolant temperature (ECT) sensor.
Data was captured using a USB terminal app on an Android tablet.
Above is a screen capture of the USB serial data which was also logged to a file.
The file was uploaded and copied into Excel.
Above is a plot of the 10 second ECT samples over the test run.
This car has electric fans on the radiator, but they do not operate until well over 100°, but the normal coolant thermostat can be see operating a little in this plot. On another trial the thermostat seemed actively controlling in the range 70-80°.
On the 80km/h open road, temperature did not exceed 65°, outside air temperature was 10°.
An earlier trial had problems with data capture, some log data was lost.
The route involved some steep climbs, albeit at lowish speed.
Above the route profile.
Above, the speed graph.
A work in progress…