i ask about VM140,
1- what is the input signal sensitivity? can i use it with thermocouples that produce signals about some mV ?
2- does the card has a built in amplifier, if yes what is the gain?or its adjustable and how can i set it?
thak u

Please read the specs under the photo on the product page: you can find all information there.
All details you can always find by following the download link on the product page: there you can even find the complete manual.
For a few mV this card is not suitable and no amplifier also, but if you know something about electronics, you can tweak the card.

if i found the specifications under the photo i wouldn’t ask u, i downloaded the manual and i didn’t found the specifications that i ask about, how can i tweak the card

It is there … but now I understand: you don’t know how to recalculate these specifications for your project:
It says inputs: 0…5 Volts and 10 bits resolution (=1024 possible values). So minimal step/sensitivity is in the best case 5/1024 = about 5 mV. As you have also noise and conversion errors, you can’t trust on this for measuring signals of a few mV’s.
Tweaking: adapt the input amplifier to have more gain. No values: please experiment if you know what you are doing (or you can destroy your card).