Anders_P42
Well-Known Member
Or buy the one I posted in post 5 that measures up to 550C. Extra temp range useful as can measure hotter parts of engine.
They work by detecting the infrared heat emitted by the item. They are more accurate with black items with high emissivity and poorer with shiny things like stainless.
Been using one of these for several years. Bought it to calibrate my home-made exhaust temp alarm - components for alarm cost under a tenner - the thermometer about £15. Exhaust alarm proved its worth a few weeks ago with a failed coolant impeller.
Someone tell me how these thermometers work please. And are they accurate? Can I zap a baking tray in the oven and get the oven temperature?
How about one for half that price: http://amzn.to/1pL7bat
Our local Lidl still had plenty in stock yesterday.
Surely the O.03, 0.02,0.04 numbers should be 1.03,1.02,1.04. Otherwise the corrected temperature is only 3% of the reading.As Keith-i has said, they are subject to error due to differing emissivity of different materials
To correct the reading on the unit, multiply it by the factor below.
Aluminum foil 0.03
Aluminum, anodized 0.9
Asphalt 0.88
Brick 0.90
Concrete, rough 0.91
Copper, polished 0.04
Copper, oxidized 0.87
Glass, smooth (uncoated) 0.95
Ice 0.97
Limestone 0.92
Marble (polished) 0.89 to 0.92
Paint (including white) 0.9
Paper, roofing or white 0.88 to 0.86
Plaster, rough 0.89
Silver, polished 0.02
Silver, oxidized 0.04
Snow 0.8 to 0.9
Water, pure 0.96
Some of the values are not what one would expect but Wikipedia could be wrong
Surely the O.03, 0.02,0.04 numbers should be 1.03,1.02,1.04. Otherwise the corrected temperature is only 3% of the reading.