I am writing small weighing scale software(com1) in that i have caught data after scale gets stable. so can i use sleep method in the thread till scale gets stable?

Yes you can use, but instead of thread sleep we can trigger handler which is used to capture data when scale get stable.

yes you have to sleep thread for a time . most of time weighing machine does not return correct weight. also you have to calibrate weighing machine before start weight checking .