HT-18 Thermal Imager Macro Mod

While working on the improved actuators for SMMB, I wanted to be able to perform some quantitative experiments to design the thermal transfer of the controller board and enclosure.  I figured that feeling with my fingers probably wasn’t scientific enough to make consistent progress.

Enter an inexpensive Chinese thermal imager, which you can find for under $300 from time to time.  A non-affiliate Amazon link:

HT-18 Thermal Imaging Camera

It has a resolution 220×160, reads up to 300C and being intended for construction inspection has at least a little software support for reading out actual temperatures and capturing images for reports.  The only downside is the focal length.  It really can’t focus on anything less than about a meter away.  That isn’t too great for PCB inspection.

Enter this eevblog thread, describing at least one person who added a lens for a macro mod.  I gave it a try, getting an appropriately specified laser cutter lens from Amazon:  ZnSE w/ approximately 100mm focal length labeled as “Laser Engraver”.  A non-affiliate link for the exact one I got is:

I could have 3d printed a fancy lens mount, but decided I would see how well a quick and dirty hot glue gun job would work:

Macro lens mount
Macro lens mount for HT-18 Thermal Imager

And the answer is pretty good —  I can resolve individual 0603 components on the board just fine.