3 ms·

I have an infared thermometer I've been using for cooking, and it often gives readings that vary quite a bit. Now some of that is measuring the actual variance

I have an infared thermometer I've been using for cooking, and it often gives readings that vary quite a bit. Now some of that is measuring the actual variance of temperature at different points in the pan / pot / etc. But I've also pointed it at myself and got readings that weren't super consistent and definitely weren't core temperature - I think I usually see around 93 on people with it. Generally those readings can vary a few degrees even if you are using it well. It's just not made to measure fractions of a degree. So I was wondering how infrared could possibly work... Not really surprised it doesn't, but the stats at how bad it has been in the past (h1n1, Ebola) are shockingly bad. I guess I was hoping there was some medical variant of these thermometers, which is accurate in the 95-105F range, and the cooking thermometers just sacrificed accuracy for range. But it sounds like that's not the case.

function_seven 6y ago
The medical versions are different. They're not just reporting the actual surface temperature of the user's forehead. (Which is going to be a few degrees lower than core body temp) They compensate. I have an iHealth unit that Wyze was selling a few months ago. I check my temperature several times a day. I believe it's quite accurate. In the mornings it'll read 98.2˚F, afternoons I'm at 98.4˚F, and just before bed it'll read either 98.4˚F or 98.6˚F. The fact that it's this consistent with the intraday variation gives me some confidence in it. But, granted, I have yet to have a fever. (That I know of!) I'm not sure what it uses to arrive at the answer. It could be as simple as adding a fixed constant or multiplier to the forehead surface temperature. Or it could separately measure the ambient temperature and factor that into the radiant heat coming from my forehead to arrive at an answer.
- extrapickles 6y ago
  The medical ones probably only take into account the average emissivity of human skin (which varies somewhat by race/genetics, which they do not account for).

function_seven 6y ago

The medical versions are different. They're not just reporting the actual surface temperature of the user's forehead. (Which is going to be a few degrees lower than core body temp) They compensate. I have an iHealth unit that Wyze was selling a few months ago. I check my temperature several times a day. I believe it's quite accurate. In the mornings it'll read 98.2˚F, afternoons I'm at 98.4˚F, and just before bed it'll read either 98.4˚F or 98.6˚F. The fact that it's this consistent with the intraday variation gives me some confidence in it. But, granted, I have yet to have a fever. (That I know of!) I'm not sure what it uses to arrive at the answer. It could be as simple as adding a fixed constant or multiplier to the forehead surface temperature. Or it could separately measure the ambient temperature and factor that into the radiant heat coming from my forehead to arrive at an answer.

extrapickles 6y ago
The medical ones probably only take into account the average emissivity of human skin (which varies somewhat by race/genetics, which they do not account for).