Need advise on deciding temperature sensor

[aspired]

I would appreciate some adivce on deciding what temperature sensor to use. The range of the application is limited to 32 -42c. It will be used to measure temperature of the body at various sites. It should be very small ( around 0.014inches) The most important aspect of the sensor should be that it should have a resoltuion of 0.05 or even better. I am planning to use the PCI 4351 for measurements, so as far as the electronics is concerned I am sure that resolution will not be a problem. However, when I contacted several thermistor manufacturers I was told that the resolution only depends on the electronics. I am not sure at all if that is correct. So what parameters of the sensor itself should I be inquiring about?. What is the rel
ationship between accuracy of the sensor, sensitivity and resolution ? HOw does one define the resoltion of the thermistor?.Does greater sensitivity of the sensor mean better resoltuion? Does the size of the thermistor affect its sensitivity/resoltuion?
If I decide to use a thermocouple, then what parameters should i be looking at to get the required resolution?

[PdB]

Generally TCs are used in industrial measurements in a wide temperature range (-100 to say +1000 degrees C).
Thermistors are typically used in narrow temperature-ranges where resolution matters (say 20 degree range).
In a thermistor measurement we built we reached a 0.1 mK resolution. With the same hardware (switching from R to Volt) we only reached a 10 mK resolution).
Too find it out yourself, order a TC and a thermistor and compare the results.
However, the thermistor must be calibrated and lineairised. TC output is much more standardized and gives less calibration problems.

[Buechsenschuetz]

The resolution of a temperature sensor itself is not limited. The limits of resolution are given by the data acquisition system together with the sensitivity (mV/K or ohms/K) of the temperature sensor. In case of a resistive temperature sensor, you will have to provide a convenient supply voltage. But - be careful not to supply the sensor with too much current. The heat dissipated in the sensor will heat it up, so the current across a resistive should be as small as possible.

The size of the temperature sensor determines mainly the time contant (i.e. reaction time) of the sensor.

Don't forget to provide proper physical contact (i.e. a good heat conductive contact) between the object and the sensor. In many cases this can be achieved using heat conductive
paste, as used on heatsinks. There are some thermocouple sensors providing a spring-loaded contact to the object.