Engine temperature with infrared thermometer

[leftbrainstuff]

Infra red devices are very useful. They measure block body radiation, not temperature directly. All metals have well known emission curves for temperature changes that dont involve a change of state. They are relatively insensitive to surface finish at the temp ranges we are interested in.

Previously we had to use temperature sensitive paints, max temp indicator strips and instrumented thermocouples. Much less convenient than the hand held devices.

I have calibrated the hand held devices. They are consistent for steady state temperatures which is more important than their absolute calibration.

If you keep a log of temps then you'll have a baseline for troubleshooting. On the engine for example you are looking for hot spots or unexpected variance on cooling system or exhaust components.

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[SeaSon]

I'd wager the cheap ir meter is more accurate than your mechanical gauge-wire-sender combo. It's a great peace of mind tool, as is a battery load tester.

[thinwater]

Originally Posted by Tkeeth

Flat black electrical tape works better, it has an emissivity at about .95. Also be aware, the laser pointer is a marker and has nothing to do with measurment. In the side of your device will be a cone that will give the size of the measurement spot at a certain distance. You generaly want to be closer. Paul is correct. I am a IR professional 20+ years

A spot of flat black paint is even better. I often marked stainless process equipment this way, since stainless will read WAY off. This is what I would do if it were more than a on-time glance.

[bustermaw]

Originally Posted by jalfrezi

I was given a laser point infrared thermometer. A great gadget.
I have been pointing it at my d2-40 and note varied surface temperatures.
The thermostat temperature measured with it is 85c whilst the gauge says 90degrees c.
Any comments please.
Gareth of Jalfrezi


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Gareth Thomas

Go with the IR.
I was pulling my hair out with an overheating engine when a friend came over
with his IR thermometer and found out it was a faulty temperature gauge

[StuM]

I bought my first IR thermometer right after a delivery trip in a trawler.

We thought we had an overheating problem with one engine until we stopped in Cooktown and borrowed an IR thermometer from a local fishing boat