I think this might be a “yes, but no” kind of thing.
Yes, these are test strips. Yes, they change color to indicate a reading. Yes, they use chemical reactions to cause that color change.
AFAIK: No, these aren’t for testing blood. No, these don’t seem to be for consumption by an electronic meter. And no, I don’t think this is what OP was asking about.
Like, there’s probably some good info, but not for this thread specifically :P
Source: Pulling it straight out of my ass, but it is informed by my limited experience with medical test equipment, and much less limited experience with electronics.
lvxferre@mander.xyz 5 days ago
Those are used with urine, not blood. Urine is yellow-ish, but since it’s just a drop, it doesn’t stain the strip; instead, the blue tip changes colour as it reacts with the glucose in the urine. Then you compare that coloured tip with a chart, and you get an idea of the concentration of glucose in your body. Picture related:
Image
I remember seeing those bottles in my bathroom all the time as a kid (my sister is diabetic).
It is roughly the same idea as the one behind the litmus test for pH, indeed. The difference is which substance you’re putting there (Benedict’s reagent vs. pH indicators) and which substance you’re testing for (glucose vs. H₃O⁺ / OH⁻).