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Measuring higher temperatures

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(@pugwash)
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Joined: 4 years ago
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How to measure temperature with just a piece of copper wire and no need for expensive thermocouples.

@robo-pi You may be interested in this for your water boiler.

Subjecting sensors to long periods of high temperature and humidity or submerging them is not going to do them a lot of good and will certainly reduce their lifespan.

The following technique is used in my profession to measure the change in temperature inside an electric motor during performance testing. The resistance R1 of a winding in the motor is measured prior to the motor being switched on and again R2 after a prescribed time period, usually a couple of hours. Once you have the base reference resistance it is possible to monitor the temperature over days, weeks, months or whatever time period you choose.

This is the formula need to calculate the temperature. Sorry, America this is in Celsius!

t2 = ((R2/R1) - 1)/0.004041) + t1

where:

t1 = Initial Temperature
t2 = Final Temperature
R1 = Initial Resistance
R2 = Final Resistance
0.004041 is a coefficient specifically for copper (change if using other materials)

My tip: Use the longest piece of wire practical.


   
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(@pugwash)
Noble Member
Joined: 4 years ago
Posts: 1012
Topic starter  

Sorry, I missed one parenthesis in the equation, it should read:

t2 = (((R2/R1) - 1)/0.004041) + t1


   
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