1. Unlock the retaining screw. Press the gauge legs beyond the barrel.
2. Insert the legs (wires) into the root gap space or the two pieces of pipe to be fitted. Turn the gauge 90, being careful to apply a constant back pressure to the barrel.
3. Hold the gauge as square as possible with the fitting to obtain an accurate reading. Lock the retaining screw. Reverse the 90 turn and remove the gauge. You’re now ready to read the increment opposite the red line.
4. When the red line aligns with the 1/32 increment line you have a good internal alignment and fit-up. Misalignment can be determined from the zero line by increment markings of 1/16 inch.