I am building an infrared contactless thermometer using this sensor, the MLX90614, but I always face the same problem.
Firstly, I bought the BAA version of that sensor, but it always measured lower temperatures than it should. I thought it was because of the wide FOV, so I secondly bought the DCC version, which supposedly was more accurate. However, I still had the same problem, so I ended up buying the most expensive one, the DCI version, which has medical accuracy and a FOV of only 5 degrees. However, I still have now the same problem.
When I place the sensor maybe 0.5 cm away from my forehead, it always measures lower temperatures than it should. It measures 34 celsius degrees or so, and human temperature should be something closer to 36 or 37 degrees.
I am using the example program of the Adafruit library, so I believe the code is correct. What should I do? Should I recalibrate it somehow?
Thanks in advance!