The short answer is no…how would you do this? How would you know where along the wire the temperature was valid? The temperature is determined by a voltage drop at the junction formed by the connection between the two different types of wires. That is the point that affects the temperature. I hope this helps. Take care.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Chris Savage Parallax Engineering
Thermocouple accuracy is also dependent on the quality and ambient temperature of the hookup wire connections. Each series connection generates a series voltage, which contributes to the net voltage measured. For that reason, you want just the tip of the thermocouple at a high temperature, and let the wires cool down over a long distance before you make your hookup wire connections. Good info at http://en.wikipedia.org/wiki/Thermocouple
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ·"If you build it, they will come."
What about a resistance thermometer? What I need is a sensor that can figure out if any point on a wire gets above 90C. I don't care where it is I just need to make sure it doesn't go higher than 90C.
You could place any number of thermistors along a wire and monitor them seperately with a stamp, or 4 thermistors per LM339, which is a quad comparator.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ·"If you build it, they will come."
what is the voltage/power requirement for a LM399, if i am correct in assuming that you connect it to a voltage and it either goes logic high or low when a voltage is above a set current correct?
Be advised: the LM339 has 4 useful, but very spiteful comparators inside. Sometimes we only need one or two and the rest go unused. Ground all the pins of the unused, unloved and unfulfilled comparators, or they may induce unwanted oscillation in the ones you are using.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ·"If you build it, they will come."
Just FYI they do make some TC's that have multi-junctions that are parralled together. This causes a reading of avarage TC temp.
And for more fun if you ever need a TC cheap, just get some thermocouple extention wire( it is made out of the same stuff as a TC) and use a TIG welder to weld the wires together at the end you want to have a TC. I have done this and tested it. Works decently.
Comments
The short answer is no…how would you do this? How would you know where along the wire the temperature was valid? The temperature is determined by a voltage drop at the junction formed by the connection between the two different types of wires. That is the point that affects the temperature. I hope this helps. Take care.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Engineering
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·"If you build it, they will come."
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·"If you build it, they will come."
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·"If you build it, they will come."
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·"If you build it, they will come."
And for more fun if you ever need a TC cheap, just get some thermocouple extention wire( it is made out of the same stuff as a TC) and use a TIG welder to weld the wires together at the end you want to have a TC. I have done this and tested it. Works decently.