# Infra Red Thermometer maplin



## geckomagic (Feb 27, 2007)

Just seen these on sale at maplins
Infrared Thermometer > Maplin

only £20 reduced from £40, 
Is it worth buying or are there better ones around at a similar price??
Accurancy is the bit im worried about it says ±2.5% of reading or 2.5°C / 4.5°F, does this mean it could be 2.5c higher or lower? If so thats not very good.

Specifications: Temperature range:-35 to 365°C (-31 to 689°F) Temperature resolution: 0.2°C / 0.5°F Emmissivity: Fixed at 0.95 Optical resolution: 8:1 distance to spot size ratio Basic accuracy: ±2.5% of reading or 2.5°C / 4.5°F Response time: <1 second Diode laser: Output <1mW at 630-670nm class II laser product Power supply:2 x AAA battery (Order Code L42AL) Weight: 113g Dimensions: 63.5(w) x 33.9(d) x 166.4(h) mm


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## fixitsan (Apr 15, 2008)

kris.hollands said:


> Just seen these on sale at maplins
> Infrared Thermometer > Maplin
> 
> 
> Specifications: Temperature range:-35 to 365°C (-31 to 689°F) Temperature resolution: 0.2°C / 0.5°F Emmissivity: Fixed at 0.95 Optical resolution: 8:1 distance to spot size ratio Basic accuracy: ±2.5% of reading or 2.5°C / 4.5°F Response time: <1 second Diode laser: Output <1mW at 630-670nm class II laser product Power supply:2 x AAA battery (Order Code L42AL) Weight: 113g Dimensions: 63.5(w) x 33.9(d) x 166.4(h) mm



You're correct in your assumption, the instrument only measures temperatures to within +/- 2.5 degrees C of what they actually are.
Normally, the error is linear, so if it is 1 degree too low at 10 degreesC it is also reading 1 degree too low at 32 degrees C. If you have an accurate thermometer you can easily get an idea of which way and by how much your error is working and apply a correction factor.
(My wife does this with the bathroom scales all the time  )

Believe it or not, at that price the accuracy is quite good.
I just looked at RS components, who sell the most high quality instruments, and even the Fluke range of non-contact thermometers (starting at about £70) also only have a +/-2.5 degree accuracy. You need to pay over £100 to get better accuracy, they sell a model with +/- 2 degree celsius accuracy for £127.


Chris


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## Bosscat (Sep 1, 2008)

Try the TN2 it has a ±2% of reading or ±2°C whichever is greater - cheapest you can get them for is from thermometers for you for about £23


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## geckomagic (Feb 27, 2007)

for £20 I think i'll get one and compare it to y other digital thermometers
Thanks


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## robglobe (Feb 11, 2007)

I bought 1 of these and have compared it side by side with a TN2 thermometer and they both read roughly the same temps with only 0.5 difference between them.


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## ady365d (Sep 10, 2008)

would i be right in thinking that these only measure the temp of a surface , and not of air , if been looking at a few but all the ones iv seen only measure objects ??


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## fixitsan (Apr 15, 2008)

ady365d said:


> would i be right in thinking that these only measure the temp of a surface , and not of air , if been looking at a few but all the ones iv seen only measure objects ??


Yes, they're non-contact surface temperature thermometers.
Probably almost all other thermometers will be able to measure air temperature, just not this particular type.


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## fixitsan (Apr 15, 2008)

robglobe said:


> I bought 1 of these and have compared it side by side with a TN2 thermometer and they both read roughly the same temps with only 0.5 difference between them.


Out of interest , how accurate is the TN2 compared to a known calibrated thermometer ? The reason i ask is that a lot of the time manufacturers of the sensors in these work to fairly high standards and the quoted tolerances are often worse than what is achievable in practice


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