Hints about high-precision NTC front-end

[_Mark_]

Hello,
I need to measure a temperature between 0 and 60 °C, with an accuracy < 0.1 °C in the range of 15 to 40 °C.
It's not a one off design, so I'm afraid about the repeatability among different items or the time (and cost) needed for a calibration.

On board there is an MCU with a 11-bit ADC which I would use.
I wonder which is the best way to design the front-end (I know there are several circuits) in order to meet the requirements and keep the costs low.

Unfortunately I need to use an NTC, it's a design constraint.
Thanks in advance
Mark

 

[chuckey]

I am not sure that you can get the repeatability with a NTC Thermistor, I would go for ;- **broken link removed** . they seem to give calibration results for accuracy in the order of .13 degs C, Better then this, is a platinum thermo couple.!!with all its shortcomings, are you sure you need .1 deg C?
Frank

 

[ArticCynda]

Probably a PT100 can most likely provide you with the accuracy you need, of course at a high price.

 

[crutschow]

Doubt that you can get <0.1°C accuracy with an NTC, certainly not without a lot of calibration for each unit. Why are you constrained to use that?

 

[FvM]

High precision NTCs like Cantherm MF51E might be able to achieve the specification, probably requiring sensor grouping.

These sensors are often used for medical thermometers. I'm under the impression, that the B tolerance could be already too large for 15 to 40 °C range. I also guess that it would be better to avoid the additional errors introduced by a 11 bit ADC.