Which buffer solutions should we use to calibrate pH meter?

Wide range of buffer solutions for a variety of applications available. However, for 99% of the time buffer 7 and buffer 4 solution are the two you need to perform a calibration.

If you are measuring mostly in the alkaline scale, then you might use buffer 7 and buffer 10, although buffer 10 is not as stable a solution as buffer 4, and therefore has a much shorter life once exposed to air.