Pneumatic Test with U-Tube Vertical Manometer

It is the total difference between the upper and lower liquid levels. In your example, 70 mm H₂O.

Thank you for your kind cooperation.

You are most welcome. Your question may have seemed naive to some viewers, but it is a perfectly good question. It is easy to be confused about this, among many other issues relating to fluid pressure between one column and another. I don't know what the best textbook references might be on this topic, but you have posed this in a way that was easy to explain. Good luck in your studies and work.

Thanks again for your reply.

May ı take your e-mail adress

It isn't advisable to give email addresses in open forums like this, because search robots will find them and then generate lots of spam. However, you can do so by altering the format, as in tornado[at]kpunet.net. Please feel free to write.