The output of the regulator is measured in ounces of pressure, and finding a guage to measure that is going to be difficult at least. Most RV repair/service places will just replace the thing because they are not too expensive.
However, haveing said that, the pressure is easy to adjust. If you want to try it, I would suggest you first enlist a helper. Take the screw off plastic cap off the center of the regulator. It will be on the opposite side of the 3" +,- round thing, and under that cap you will see a stamped metal piece with a screwdriver slot in it. With your helper watching a full on burner on the stove top, slowly turn the stamped metal piece clockwise until you get a good flame on the stove. You shouldn't have to turn it more than a half turn. If it does not adjust, or does not adjust correctly, replace it.
I'm sure I will hear screams of protest here claiming you shouldn't be messing with a regulator, and if you feel that way, please don't mess with your regulator.
Oh, almost forgot...welcome to the forum.