Pressure Canning Dial Gauge Testing for Free

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Dial gauge pressure canners need to be checked for accuracy each year.

Why is this important? Over time as the canner lid is handled, bumped, or just used, Pressure Cookerthe calibration of a dial gauge can become inaccurate. If it is off just a little bit, you may not notice the inaccuracy.

Research tested recipes for pressure canned foods are based on specific temperatures and times to kill harmful bacteria. If the pressure is lower than that recommended for processing, the internal temperature of the food will not be adequate to kill all the bacteria and spores. Spores that survive can produce harmful toxins that can cause illness or death. Although a jar may seal if processed at a lower temperature, it does not mean that the food inside the jar is safe. Processing foods at too low a pressure is a safety issue.

If a dial gauge is inaccurate and the processing temperature is higher than recommended, the food inside the jar may be overcooked and softer in texture than desired. This is not a safety issue but is a quality issue.

If the dial gauge tests off by less than 2 pounds, you will need to adjust the pounds pressure you use when processing the foods. If a gauge tests off by more than two pounds, the dial gauge should be replaced. Also, a gauge should be replaced if it is cracked or the glass covering is missing.

The test only takes a few minutes. Only the lid is needed for testing. Pressure canners with a weighted gauge do not need to be tested for accuracy because they cannot go out of calibration.

A Chatham County Cooperative Extension Family and Consumer Sciences educator is available to test dial gauges. You can get your pressure canner gauge tested at the Chatham County Extension Center for free. Only dial gauge canners can be tested. Older models may not fit the tester. To get your dial gauge pressure canner tested, please contact Phyllis Smith at 919-542-8202 or reach her through email at

Written By

Photo of Tiffany HancockTiffany HancockCounty Extension Support Specialist (919) 542-8202 (Office) tiffany_hancock@ncsu.eduChatham County, North Carolina

Contributing Specialist

Photo of Phyllis SmithPhyllis SmithExtension Agent, Family and Consumer Sciences (919) 542-8247 phyllis_smith@ncsu.eduChatham County, North Carolina
Posted on Mar 24, 2016
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