Greetings!
The final resistance of a temperature sensor is always going to be an asymptotic function....in other words, it NEVER actually reaches the final resistance, but approaches is exponentially. However, this can be minimized by a couple of tricks...one is called an Anticipator, where you artificially force the temperature of the sensor to overshoot, thereby bringing the temperature up to its final value quickly. Your best bet is to do a few tests, and find out when the resistance reaches 67% of its final value. (an analogy to an RC time constant.) You can use this as a first order figure of merit. From there, you can figure out what the "time constant" of your sensor is, and use that as a base line for how often you can expect to take a reading.
The best routine to use in Labview is probably to take samples at regular intervals, and then compare subsequent readings. If there is more than a certain percentage of change, then you need to take a few more readings. This is fairly easy to do in Labview with loop iterations.
Hope this helps some. This sort of calibration always needs a bit of real world 'tweaking" but you should come up with a practical solution pretty quickly
good luck!
Eric
Eric P. Nichols
P.O. Box 56235
North Pole, AK 99705
