Q. How to read the pressure of a manifold gauge?

Answer

The high pressure is on the right (red) side of the manifold, which is also where the red gauge is located on the instrument. The low side of the manifold is located on the left side, which is blue, and the gauge that is blue is the vacuum/pressure gauge. One is able to examine the pressure and vacuum readings by going via separate channels that go from the low and high side fittings to their respective gauges. Internal channels inside the manifold body serve to link each of the three fittings to one another.