The weights are set to rock at an additional 0.5 lb. pressure so the 10 lb rocks @ 10.5 and the 5 lb rocks @ 5.5. That is actual pressure - not what the gauge says. But the gauge is just meant to be a general guideline anyway (per the manual), which is one of the many reasons for recommending the weights and for discouraging those with only a gauge from playing with the heat so much while trying to PEG that 11 lbs. that they end up with siphoning. Weights are accurate; gauges aren't so go by the weight and just ignore the gauge. The difference you are seeing is likely due to the decreased resistance as the pressure rises. At lower lbs./sq. inch the gap would be higher as lower pressure discrepancies would be more difficult for any gauge to measure accurately because of increased resistance. I think it is kind of like when you try to blow up a balloon. There is less resistance as the balloon gets bigger so it gets easier to blow up. Length of time also plays a role. If you let the 5 lb weight ride for 30-45 mins or so the gauge would eventually settle down to a closer reading. Bottom line - ignore the gauge. ;) Dave

raspberrytart - since you have that treasure of an old stove that deserves to be preserved and well cared for then a separate burner would be your best bet IMO regardless of which canner you buy. Skip the canning element - if you could even find one that would fit your stove - to avoid any damage to the stove. The 16 qt Presto gets excellent reviews and will handle most anything you want to PC without the extra weight and size of the 23 qt. Rather than a graniteware canner you could consider a small, deep stockpot (discussed in several threads here) in a 12 or 16 qt size with a flat bottom for about the same price or even less and add a small rack in the bottom. It has sufficient size and also much less weight and is faster to heat up. But many of the available electric stand-alone burners simply aren't powerful enough to can with and cost much more than a good stand alone propane burner such as the one from Northern Tool linked in several discussions you have likely read already. Plus they are often even smaller than the burner on your stove and some don't heat large pots evenly or can damage counter tops with the trapped heat. If you have a gas grill then the burner is all you'd need to can outside as many of us do. That gas burner will handle ANY size pot. ;) Dave

As long as it will hold and process a minimum of 4 quarts at a time it is considered safe by NCHFP standards. All the tested and approved recipes and the processing times stipulated in them are based on that minimum capacity of air/steam/temp achieved. Any less capacity all the computations go out the window. ;) With newer canners that means using the 16 quart model but if yours holds 5 quarts it should be ok. And yes, the reputable companies will still back the smaller units but for cooking only, not canning. Some off-brands claim they can be used for canning too but that is only because they don't subscribe to the USDA guidelines. Dave

If you will buy a set of weights from Presto you can use the 10 lb. weight and ignore the dial if you don't need to adjust for higher altitude. If you do live at a high altitude, just use the counterweight instead. You still leave the gauge on, just use the canner as a weighted gauge canner instead of a dial gauge. They sell the weight set. I found mine at a local hardware store cheaper than I could order from Presto. I emailed Presto, plus called them on the phone to be sure it was fine to use the weights instead of the dial. Then, I emailed Elizabeth Andress at NCFHFP and she said it was fine to do, also. We are recommending this for those who can't or don't want to get their gauge tested each year. I would not say 100% that the method you are using is accurate. Technically, it does work that way if your gauge is off. However, even them shipping that gauge back and forth can make it out of adjustment by the time you get it back.