Differential u tube manometer case 2 

Thank you bro😍😍😍

Specific weight w= density × gravity . So gravity is considred here

Above datum line also means the same bro. No problem in that

Datum line கு மேல் உள்ள pipe B fluid ன் உயரம்.

@@100Engineering ok sir

Used in R & AC and in industries. But nowadays digital meter is used, directly we can see the pressure difference.