Fill the jar to within ½ inch of the brim with water.
Tighten the lid onto the jar. Apply adhesive caulk around the lid's lip to ensure a 100 percent airtight seal between the lid and the jar.
Drill two ½ inch holes in the jar lid. Insert two lengths of ½ inch plastic tubing into the jar. Insert one length of tubing all the way to the bottom of the jar. Insert the second length of tubing ¼ inch into the jar.
Seal the two pieces of plastic tubing to the jar lid with the adhesive caulk in order to ensure a 100 percent airtight seal.
Connect the tubing which extends to the jars at the bottom to the HHO gas output of the hydrogen fuel cell.
Direct the free end of the tubing which extends ¼ inch into the jar into the household measuring cup. Place the quart jar and the household measuring cup on the same flat and level surface, next to each other.
Connect the HHO fuel cell to a 12-volt regulated power source. Connect the electrolyte tank to the HHO fuel cell and fill the tank and fuel cell with electrolyte.
Power on the HHO fuel cell for a few seconds, providing a regulated 15 to 18 amps. As the bubbler creates HHO gas, the gas will fill the half gallon glass jar and displace fluid into the measuring cup.
Turn off the fuel cell, and empty any fluid displaced into the household measuring cup. Do not empty any fluid which fills the tubing leading from the sealed jar into the measuring cup. The fluid present in the rubber tubing serves to "prime the pump" for the fuel cell output measuring experiment.
Power on the HHO fuel cell for exactly 30 seconds, providing a regulated 15 to 18 amps. As the bubbler creates HHO gas, the gas will fill the half gallon glass jar and displace fluid into the measuring cup.
After the fuel cell is powered off, read the amount of fluid displaced into the household measuring cup. HHO fuel cells are rated in terms of liters of gas produced per minute. Since the experiment was operated for 30 seconds, double the measurement of the amount of fluid in the measuring cup. This figure equals the number of liters per minute of HHO gas produced.