lidl infra red thermometer

[Richard]

But Brian could try to contact manufacturers and point out the feasibility of the goal. He does have a vested interest.

[Dave Liquorice]

So has a reasonable thermal mass.

What sort of stat? Bi-metal clicky ones have a heater inside to reduce the hysterisis to almost acceptable levels. How do you know the stats calibration is correct?

Lower arms last night were 29 C, palm 32 C, back of hand 30 C. The nominal 37 C body temperature is the body core temperature not that of the surface of extremities.

[Andrew Gabriel]

I have the first model Maplin sold, a CNY 110.

It's probably ~15 years old now, although it did get replaced under warranty within first year. Lowest I've seen it read is -55C when pointed at high thin clouds, although this is outside its rated range.

An IR thermomenter won't be able to read a completely clear sky (which is about -270C, or 3K), but can read a very thin cloud layer which you might not be able to see.

I've bought several more over the years for other people, and have a nice CPC pocket one which also has a temperature probe and pipe contact clamp temperature measuring facility (although it's faster to use the IR sensor unless the pipe is bare copper).

[whisky-dave]

I brought one as a cat toy. :-)

I'd like to know more about the one's they're planing on using at airports that have an accuracy of 0.1C as an aid to checking for Ebola via increase in body temerature. I hope they don't have a problem with emissive black body problems ;-)

[Johny B Good]

I strongly suspect the melanin level in skin will have little effect on the readings of such IR thermometers calibrated to the appropriate emmissivity values for human skin (and, if it does, I'm sure they'll have a calibrate button marked C/N[1] to compensate for this effect :-).

In any case, a reading taken from a melanin free region (eg mouth or ear canal[2]) will bypass this 'unknown', if indeed it is an 'unknown'.

[1] C/N meaning Pnhpnfvna/Avttre [2] There'll be yet another bodily orifice or two available to the Customs & Excise officers working in the body cavity search rooms (it could be incorporated as an extra feature of the endoscope).

[Johny B Good]

====snip====

Even with no visible clouds, there's still more than enough water vapour in the atmosphere to emit infrared back to the ground and 'obscure the 3 deg K CMB', which is why I suggested a midwinter's clear night sky for this test when the water vapour content is most likely to be at its lowest.

You don't even need a thin invisible cloud layer, just the totally (optically) transparent water vapour will be sufficient on its own to get a reading.

Even bare copper should give a useful indicator since it's not so much the absolute temperature as the temperature difference that's important in this case (assuming both flow and return pipes are bare - usually the case, you're unlikely to see only the one pipe painted).

You can probably find a correction factor or else work out your own correction factor by simple experiment.

I've since googled for images of IR thermometers (mine has absolutely no indication of make or model number) and eventually came across a picture of the IR thermometer I'd bought from "Maplin Man" all those years ago (15 th page of images - bottom left on:

which linked me to:

and clicking on the link to the Elcometer website eventually led me to this page:

I saved the data sheet and user guide for future reference

According to the description the temperature range in deg Celcius is from -35 to +365 (-31F to +689F). I guess I must have mis-remembered that 400+ deg C reading on the exhaust pipes (unless I'd accidently pressed the C/F scale select button and was reading deg F - I normally keep it permanently set to the Celcius scale).

It seems to easily meet its claimed accuracy of +/- 1.5 deg C afaict. All in all, not a bad example of the breed of IR thermometer generally available to the public at large.

Thanks to this thread, I now know a lot more about my own IR thermometer than I ever did before (I can't recall whether I got an instruction leaflet with it at the time of purchase or not - probably not, I can't see any sign of one now).

[whisky-dave]

I would hope so, but who knows. I'm curuious as to how they get it that sensitive

I thought the idea was to check people remotely as they came through customs otherwise you can just stick a rectal themoeter where the sun don't shine to get a reading, and I'd have thpought a more accurate one too.

[polygonum]

Someone I know has a disorder which results in foot temperature rising above 37 C at times. Definitely detectable with our inexpensive IR thermometer. It is bizarre because there can be combinations of severe pain, redness and overheated areas - and you can end up with any combination of red/not red, painful/not painful, overheated/not overheated - often at the same time.

[RJH]

In addition to what others have said (and apologies if it's been mentioned elsewhere), there's an inverse relationship between point accuracy and distance. Unless the the entire area surrounding the point is the same temperature.

[Andrew Gabriel]

The ones I've seen in the past are simply CCTV cameras which are sensitive though into the infra-red. They can be configured to show areas above a certain temperature in solid red. When pointed to a crowd of people, you will normally see a few bright red foreheads, those bing the ones who currently have a cold. You can very quickly quickly screen loads of people this way.

Infection will generate a local hot spot as part of the body's attempt to kill the bacteria. Some non-infected inflamations will also result in locally raised temperature.

[Tim Streater]

Virus.

[polygonum]

This is neither bacterial nor viral. Uncertain origin - possibly sympathetic nervous system? Though there are several aetiologies with similar end results.

[Johny B Good]

All this 'repetition' put me in mind of "The Fall" and their track of the same name. You don't happen to be a fan of late 70s Punk Rock by any chance?

For those who missed out on this musical experience.

[polygonum]

Thankfully I missed out on the Rod Speed experience. (Kill file member.)

[stuart.srsm]

A bit late but I've tried two of these and both start well but quickly the temperature reading starts to drop. Making constant readings and then even on/off type readings over 10 minutes or so resulted in the same spot on pla sterboard wall dropping from 13 degrees to 4 degrees. Air temp was 13 degre es.

Will try it later today in a warmer room to see if it doesn't like being us ed in coolish air temps. Suspect the circuitry warms up and throws of the r eading. A bit like a resistor that increases resistance as it warms up.

But I think the first reading is pretty good, just can't cope with repeated use. Which makes it nearly useless if scanning a wall for cold spots.