Here is one of my post from last year that you might be interested in.
You can easily make a water column pressure gauge. I made mine 24 inches tall and made hash marks on the board 1 inch apart. I then fastened a 5/16 tygon tubing on the board in a U shape. My tubing is 5 foot long. To use fill the U with water to about 11 or 12 inches then lift the range burner cover and slide the other end of tubing over burner orfice and turn that burner to high. Count the hash marks between high and low point of water in U and that will be the water column pressure. You must have another propane user on at the same time to remove static pressure such as oven or furnace.//heartlandowners.org/attachment.php?attachmentid=12007&d=1297716353&thumb=1