{"id":519,"date":"2014-04-07T06:45:50","date_gmt":"2014-04-07T05:45:50","guid":{"rendered":"http:\/\/phoenixgamedevelopment.com\/blog\/?p=519"},"modified":"2014-04-07T06:45:50","modified_gmt":"2014-04-07T05:45:50","slug":"thermal-imager-progress-update-4","status":"publish","type":"post","link":"https:\/\/phoenixgamedevelopment.com\/blog\/thermal-imager-progress-update-4\/","title":{"rendered":"Thermal Imager: Progress Update 4"},"content":{"rendered":"

I have done some more research on the issue described in my previous post, regarding the Field of view of the thermopile. I have learned that, since thermal sensors operate on a different wavelength to visible light ( I believe the MLX90620 thermopile that I have been using operates between 5 and 16 micrometers) conventional optics won’t work. In fact, they will appear black to the thermal sensor. This was likely why the lens I used didn’t work.<\/p>\n

However, it turns out that there are lenses available that are specially designed for thermal sensors. The ones I have researched are called Zinc Selenide, or ZnSe lenses. They can be quite inexpensive, like THIS<\/a> one. I believe I can use one of these to collimate the light going into the thermal sensor.<\/p>\n

I am not 100% sure what kind of lens to use, there are several options. The main two are fresnel lenses and plano-convex lenses. There are many diagrams clearly showing the characteristics of these lenses to be found on the internet (I won’t reproduce them here for copyright reasons).<\/p>\n

These lenses are often used to collimate beams from lasers, so, in effect, I am doing the reverse. Instead of emitting light, a thermal sensor receives it. This shouldn’t be an issue however, the lens should still work. The main issue will be to collimate the light, rather than focus it to a fixed point, which is something a lot of laser hobbyists want to do (for burning, cutting, etc).<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

I have done some more research on the issue described in my previous post, regarding the Field of view of the thermopile. I have learned that, since thermal sensors operate on a different wavelength to visible light ( I believe the MLX90620 thermopile that I have been using operates between 5 and 16 micrometers) conventional […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-519","post","type-post","status-publish","format-standard","hentry","category-inventions","has-post-title","has-post-date","has-post-category","has-post-tag","has-post-comment","has-post-author",""],"aioseo_notices":[],"builder_content":"","_links":{"self":[{"href":"https:\/\/phoenixgamedevelopment.com\/blog\/wp-json\/wp\/v2\/posts\/519"}],"collection":[{"href":"https:\/\/phoenixgamedevelopment.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/phoenixgamedevelopment.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/phoenixgamedevelopment.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/phoenixgamedevelopment.com\/blog\/wp-json\/wp\/v2\/comments?post=519"}],"version-history":[{"count":2,"href":"https:\/\/phoenixgamedevelopment.com\/blog\/wp-json\/wp\/v2\/posts\/519\/revisions"}],"predecessor-version":[{"id":522,"href":"https:\/\/phoenixgamedevelopment.com\/blog\/wp-json\/wp\/v2\/posts\/519\/revisions\/522"}],"wp:attachment":[{"href":"https:\/\/phoenixgamedevelopment.com\/blog\/wp-json\/wp\/v2\/media?parent=519"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/phoenixgamedevelopment.com\/blog\/wp-json\/wp\/v2\/categories?post=519"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/phoenixgamedevelopment.com\/blog\/wp-json\/wp\/v2\/tags?post=519"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}