ntc thermistor accuracy

[mah]

I need accurate sensor, 0.2 degree is critical. could the 10k NTC do this?​

this is its specs.​

ntc is 10k and Koefficient B (25 C/50 C): 3950
Accuracy: ±1%
Temp. Range -40 C to 200 C​

 

[NsrMagazin]

No. 50*1%=0.5. Unless you find a way to balance it, which will mean a reference, it will not work.

 

[mah]

what about linearization range?

 

[NsrMagazin]

Can you keep it in that range?

 

[mah]

what do you mean?
i mean after linearization what is the expected accuracy?

 

[KeepItSimpleStupid]

An RTD, e.g. PT100, would be best in that range especially for accuracy. I used one for -80C to 200C.

 

[crutschow]

If you want that kind of accuracy over that temperature range, than an RTD, as KISS mentioned, would likely be the best.
But you will also need careful design to meet that accuracy.

Do you have a way to calibrate it?

 

[dknguyen]

What temperature range? Even a Class A Pt RTD is just barely that accurate around 0C. By +/- 50C, it has exceeded that error. Do you need accuracy? Or repeatability?

http://www.thermometricscorp.com/acstan.html

 

[be80be]

"repeat ability" Is about the best you could hope for

 

[mah]

I need to read a range from 35 to 39 with accuracy and repeatability or at least accuracy. I need it accurate to 0.2 degree.

 

[Nigel Goodwin]

I need to read a range from 35 to 39 with accuracy and repeatability or at least accuracy. I need it accurate to 0.2 degree.

How are you planning calibrating it to 0.2 degrees?, you will also have to calibrate it across the entire range as it's not linear, and use a lookup table to convert the readings. Repeatability is much more likely than accuracy.

I'm somewhat dubious about getting 0.2 degrees accuracy?, would 0.5 degrees not do? - if so you could use the DS18B20 which requires no calibration.

 

[mah]

it is mentioned in this https://ram-e-shop.com/product/12vd...ntroller-10a-thermostat-control-switch-probe/temperature controller that it has accuracy 0.2 C, how did they do it?

 

[dknguyen]

it is mentioned in this https://ram-e-shop.com/product/12vd...ntroller-10a-thermostat-control-switch-probe/temperature controller that it has accuracy 0.2 C, how did they do it?

I'm not sure I believe that from something at that price point.

 

[Nigel Goodwin]

it is mentioned in this https://ram-e-shop.com/product/12vd...ntroller-10a-thermostat-control-switch-probe/temperature controller that it has accuracy 0.2 C, how did they do it?

You're rather assuming they do - if that's what you need, why not just buy it?.

 

[mah]

because i want to do it not to buy it. that's why i posted here to ask is this possible?

 

[Nigel Goodwin]

because i want to do it not to buy it. that's why i posted here to ask is this possible?

Then do it, accuracy is down to how well you build it, and even more so to how well you calibrate it - at least you have a nice low range you need to cover, so the calibration lookup table won't be too big.

 

[be80be]

For 10 dollars I'd buy the one posted and have a look at it
I don't see it being that good