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I would like to measure the temperature of a heating wire (tungsten) that's wrapped around my sample. Does anyone have a better idea than using a infrared thermometer, which has relatively low accuracy? The expected temperature will be between 200-400°C

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    $\begingroup$ perhaps a thermocouple $\endgroup$ – M. Enns Oct 24 '18 at 16:36
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    $\begingroup$ How about looking up the temperature coefficient of resistivity of tungsten and using that to get the temperature of the wire? All you would need to do is measure the voltage and the current through the wire. $\endgroup$ – Samuel Weir Oct 24 '18 at 17:14
  • $\begingroup$ @SamuelWeir I think that will get you the temperature of the wire in free air. This wire is in contact with a material and heat will transfer to the material. $\endgroup$ – Bob D Oct 24 '18 at 19:22
  • $\begingroup$ @Bob D - Yes, heat will indeed transfer to the material that the wire is wrapped around, but regardless of that the increased resistivity of the wire itself will be determined by the temperature rise of the wire. $\endgroup$ – Samuel Weir Oct 24 '18 at 19:37
  • $\begingroup$ @SamuelWeir But won't that give you some kind of average temperature of the wire. Won't the surface of the wire facing away from the material be at a higher temperature than the surface in contact with the material. I guess it depends on what the OP wants, the hot spot temperature or the average temperature. $\endgroup$ – Bob D Oct 24 '18 at 19:42
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If you can afford it, a thermal camera (e.g., FLIR) should do the job.

It determines the temperature of objects based on their infrared radiation.

There are plenty of models with different characteristics and features - you'll have to choose (buy, rent) a model, which will be optimal for your expected applications.

It would require some tuning and calibration to take into account emissivity of the wire, temperature range, etc., but, in the end, it'll give you a lot of useful information.

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  • $\begingroup$ @CPE Just keep in mind that for a good thermal contact, the thermocouple will likely be electrically connected with the wire, which may present an issue, if the voltage you use to heat up the wire is high and the TC device is not properly isolated. $\endgroup$ – V.F. Oct 26 '18 at 15:22

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