This is a follow-up question from this other question
I followed of the user Jot (get the sensor away from the sun and use a delay in arduino program)
But the results are still varying.
I recorded the temperature measured in the sensor, the temperature measured using a mercury thermometer and calculated the difference. The data was collected within 8 days
Here's the data (sorted):
SENSOR THERM DIFF
32.69 31.25 1.44
32.00 30.25 1.75
31.94 30.50 1.44
31.87 30.50 1.37
31.44 29.50 1.94
31.00 29.00 2.00
30.75 29.00 1.75
30.50 29.00 1.50
30.44 28.80 1.64
30.31 28.90 1.41
30.25 28.75 1.50
29.87 28.00 1.87
29.81 28.00 1.81
29.81 28.00 1.81
29.81 28.25 1.56
29.75 28.20 1.55
29.69 28.00 1.69
29.56 27.00 2.56
28.75 27.25 1.50
28.69 27.00 1.69
28.56 27.00 1.56
28.44 27.00 1.44
28.25 26.80 1.45
28.00 26.50 1.50
28.00 25.50 2.50
28.00 25.00 3.00
27.75 25.50 2.25
The average difference is around +1.76°C but that's not linear, and as you can see there are fluctuation in the same sensor value, 28.00 has three associated temperatures(25.0, 25.5, 26.5).
I'm not sure what to do, if the difference was regular I could simply subtract that from the sensor readings, but it seems that it varies a lot(Min: 1.37°C, Max: 3.00°C)
Any ideas?
THERM_HAT=SENSOR*1.10237- 4.81422
per ` summary(fit<-lm(THERM ~ SENSOR,x))` in R.