What would 70 psi read on a psig guage?

55.3040506

Via here

Thanks!

Wierd, I tested the guage and it’s in PSI, but it has PSIG on it. Whatever.

The only difference is what the pressure is measured in relationship to.

Most gauges measure relative to normal atmospheric pressure (~14.7 psi) whereas others read from absolute vacuum (0 psi) while others read relative to the local air pressure which may or may not be 14.7 psi.

Unfortunately, psi is often used where psig should be used, thus causing the sort of confusion you are experiencing.

gauge

Most likely you are measuring relative to atmospheric pressure. Is there a reference port on the back of the gauge?
Here is a way to clarify what you a re seeing
Blow into a tube that is connected to the gauge. You can only blow a few psi max. If the gauge reads barely above 0 you are reading “psi” If it is reading 15–16 it is reading “psig”.
Have fun with your new toy.