How to use a Thermistor
How to use a Thermistor
(OP)
Hey can some one give me a quick run down on how to use a thermistor. After some googling, I see that it is common to use the Stienhart-Hart equation. Unfortunately this does not seem to coincide with the info I have. The manufacturer states that the thermistor has a resistivity of 100ohm at 25C and a thermal coefficient of resistance of 2200ppm/C. It is supposed to be linear, but I cant crunch the numbers to match a provided graph.
Someone please fill in the blanks here.
Thermistor paste obtained from:
http://www.electroscience.com/resistor.html
Someone please fill in the blanks here.
Thermistor paste obtained from:
http://www.electroscience.com/resistor.html





RE: How to use a Thermistor
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: How to use a Thermistor
If did have more info, I just might be able to figure it out on my own. Thats why I am asking you guys, because I am lacking quite a bit of info on what the heck is going on.
From what I can see from google, all thermistors follow the same basic laws, thus it is moot that there are dozens of thermistors.
Anyway here is a pdf, pick one...anyone, they just state the resistivity and TCR. I dont know what to do with this.
http://www.electroscience.com/pdf/PTC-2600.pdf
RE: How to use a Thermistor
You linked in your second post to a page about positive tempco (PTC) thermistors. I'm not sure if you can even use the Steinhart-Hart equation for PTC. I know you can apply it to NTC thermistors. But you are better off not using the Steinhart-Hart anyway, unless you have to. On the other hand, the B-parameter equation is much, much easier to use for calculations. It is related to the Steinhart-Hart equation. Read wikipedia on thermistors to understand more about it. As I recall, NTC thermistor datasheets don't always spec B, but if they give R at two temperatures, you can calculate it.
But as I said, I'm not sure those equations even apply to PTC thermistors. Perhaps a simple linear equation works. You should look into it. Do you need PTC or NTC for your application?
RE: How to use a Thermistor
And by the way, that's not, strictly speaking, a linear relationship between T and R.
RE: How to use a Thermistor
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: How to use a Thermistor
Since what you are showing is a make-it-yourself thermistor you will need to make it then characterize it yourself.
Keith Cress
kcress - http://www.flaminsystems.com
RE: How to use a Thermistor
hey thanks guys, always helpful
RE: How to use a Thermistor
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: How to use a Thermistor