p5: simple manometer gauge pressure

Simple manometer
A basic manometer seems to be a glass tube with one endpoint linked to a place wherever pressure would be to be determined as well as the other end accessible towards the atmosphere.
There are two types of simple manometer, such as:
Piezometer
U-tube manometer
Differential manometer
A differential manometer seems to be an apparatus that monitors the pressure difference across two points.
There are two types of differential manometer, such as:
U-tube differential manometer
Inverted U-tube differential manometerp
--Byjus