Non-contact temperature measurment

[gieter]

We are considering a digital radiation thermometer to monitor temperatures during steel and iron casting in the foundry.

Does anyone have experience with it or actually uses it for comparable applications (liquid steel/iron)?

 

[NickE]

Wow good question!

I'd like to add how accurate for age hardening would you suppose these methods are?



Nick
I love materials science!

 

[stanweld]

Optical pyrometers have been used for decades in the steel industry. Digital pyrometers have been used for number of years since they became available on the market.

 

[arunmrao]

These radiation thermometers are reliable and well calibrated. The only care that needs to be taken is exposing a liquid metal layer to the thermometer. If there is a slag cover on the liquid metal or if it quickly forms a oxide layer it could lead to erroneous readings. Reason being that you are not focussing on the right target. Next important issue is to handle the instrument carefully on the furnace platform. With these simple precautions temperature measurements becomes simple and reliable for cast iron as well as steel .

 

[gieter]

What about accuracy?

I have been told that the emissivity is of great importance and should be calibrated for each alloy. If this is done well, is it possible to measure with an accuracy of plus/minus 1°C?

Does anyone have experience with measuring the pouring stream under a bottom pour ladle?

 

[JimMetalsCeramics]

What temperature range do you want to read?

 

[gieter]

Temperature range: 1200-1650°C with a particular interest in the 1450-1580°C range.

 

[kenvlach]

I have some experience with a handheld for Al alloys and a fixed device for liquid Al-Ti alloys (levitated in inert gas within a silica glass tube). arunmrao’s advice is valid for just about all liquid alloys.

Re accuracy: Omega Engineering has an online comparison chart for their handheld IR pyrometers. Accuracy improves from +3% to +0.25% as instrument price increases. So to within +4^oC for your case.

http://www.omega.com/toc_asp/frameset.html?book=Temperature&file=SEL_GUIDE_IR

Omega is a good reference info site for process measurement equipment (T, P, flow, etc.), plus they have a nice set of free handbooks which they will mail upon request.

http://www.omega.com/

 

[JimMetalsCeramics]

They make optical pyrometers for use in that range. If memory serves me it cost a few thousand dollars. But you might be able to rent one from a test equipment house.

 

[JimMetalsCeramics]

http://www.pyrometer.com/Products/Optical.htm

http://www.theheatsource.com/Pyro.htm