Initially I tested the Melexis 90614 sensor (I chose this sensor due to it's smaller field of view compared to other sensors I looked at). While the sensor worked perfectly, it was only good for short range (under 10cm) – I expected this might be the case which is why I detailed the method of narrowing the field of view in my last post. I tried that method by using a 1mm hole (in polished steel sheet metal) and placing it 1mm from sensor. Well, no luck. This only resulted in cutting the total IR getting to sensor (limited view by cutting everything else out – not by focusing field of view to smaller area, which would utilize the whole sensor).

This led me to dropping the whole idea of measuring changes in temperature of the “cheek” area due to not being able to focus a sensor on a small area from any reasonable distance. Well, that is, until I met Michael Shaub at the Hackaday Un-Conference in Chicago. Talking to him about his IR Imaging project DIY Thermal Camera , as well as his presentation of the project, gave me the motivation to look further into how these sensors can be focused on a small area at a greater distance from the sensor.

Presently testing out ideas using: Infrared Laser Thermometer Pittsburgh® - Harbour Freight item#93984 ($18.99) (which I think is the one Micheal is using). Basic specs for this are below:

• 6:1 spot size to distance ratio
• Non-contact IR thermometer pin-out
  • Data (pin D on module) to pin 12
  • Clock (pin C on module) to pin 2
  • Power (pin V on module) to diode from 3.3V supply
  • Ground (pin G on module) to ground

Test results coming soon!