In this blog, I will be using a heating plate to test for the distance to spot ratio of MLX90614 without lenses, with a copper lens hood and Fresnel Lens.
Distance to spot ratio (D:S) is the ratio of the distance between sensor and target size. The object should completely fill the FOV of the sensor.
Temperature readings vary as object moves away from MLX90614. The distance dependency can be reduced with lens hood and Fresnel lens.
OLED display is an extremely handy way of interfacing sensor readings. I2C communication protocol with only four wires to hook up the OLED.
Any voltage lower or higher than 3V might introduce temperature errors into MLX90614. A voltage compensation equation can solve the errors.
Measure the temperature with Arduino and contactless Infrared temperature sensor, the MLX90614 without any physical contact with the object.