Did you know that if you live in the US and use a pressure canner, you can probably have the accuracy of the pressure gauge tested for free? Neither did I until I read Sharon Astyk's latest work, Independence Days: A Guide to Sustainable Food Storage & Preservation. Like her earlier works, this one is excellent and contains tons of useful information for those who preserve their own foods. That's how I found out there's another way I can make good use of the state taxes we pay. The Cooperative Extension offices in most counties of the US will have someone on staff with the equipment and know-how to test a pressure canner. And they'll do this for you for free.
I got my pressure canners for free through craigslist, and they are obviously old and well used. Though I replaced some of the rubber parts that came with the canners, I had no way of testing how accurate the pressure gauges were for myself. Having now had them tested, I know that both of them read a little high around the 10 and 15 pound mark. That means I've been canning my foods at pressures that are slightly lower than recommended.
The woman who tested the canner gauges for me said that if I followed all other canning instructions to the T, I'm probably fine eating those foods. My gauges were only off by one half to one pound. (I know that with almost every canning batch I've had trouble not overshooting the recommended pressure at some point during the canning process anyway.) She said it's fine to keep using the pressure canners so long as I correct for the slightly faulty readings on my gauges.
It's good to know this about my pressure canners. If you use a pressure canner to store food for your family, I recommend you take advantage of this free testing service. After all, there's no point in preserving your own food if you can't be confident you can do so safely. With the gardening season mostly done for the year, this would be a good time have the testing done. Just so you know, you probably only need to take the lid to the Extension office, not the entire canner. But check with the person who does the testing to make sure.
More tiny tips.