Larry Lowenkron
Member
Dan is right on when he talks about screwing up a tank by putting that much pressure on it. Besides, if you remember high school physics, P1V1=P2V2. So in our 20 gallon tanks, if you pressurized it to 1.5 psi, you would loose over a gallon before you saw a 0.1psi difference. How precise is your gauge?
You can get a much more precise measurement of tank loss, WITHOUT removing the tank from the wing by just putting a one foot high column of avgas over the tank. You would need to make a tight fitting (non-leaking) connection to the tank fill, and then connect something like a 1 in. dia clear plastic tube. First, fill the tank, connect and seal the tube to the tank. Now, fill the tube with avgas, mark the top of the fluid level on the tube and wait for as long as you want since there is no standard. When you have waited as long as you want, see how much (if any) the column decreases in height. A one foot column of avgas only puts approx 0.3 psi on the tank. (P= specific weight times the height). If you want to let it sit over night, seal the top of the tube to prevent/minimize evaporation.
If you really want a precise measurement, you may need to account for temperature differences if you let it sit for too long, and the ambient temperature changes.
You can get a much more precise measurement of tank loss, WITHOUT removing the tank from the wing by just putting a one foot high column of avgas over the tank. You would need to make a tight fitting (non-leaking) connection to the tank fill, and then connect something like a 1 in. dia clear plastic tube. First, fill the tank, connect and seal the tube to the tank. Now, fill the tube with avgas, mark the top of the fluid level on the tube and wait for as long as you want since there is no standard. When you have waited as long as you want, see how much (if any) the column decreases in height. A one foot column of avgas only puts approx 0.3 psi on the tank. (P= specific weight times the height). If you want to let it sit over night, seal the top of the tube to prevent/minimize evaporation.
If you really want a precise measurement, you may need to account for temperature differences if you let it sit for too long, and the ambient temperature changes.