Mariposa County

Pressure Gauge Testing

Pressure Canner Gauge Testing

Pressure canners with a dial gauge need to be tested annually to ensure accuracy. If your dial gauge is not accurate, it is not correctly reading pressure, which may result in under-processing (unsafe food) or over-processing.

Free Testing in Mariposa

The UCCE Master Food Preservers of Mariposa County offer free pressure gauge testing at our office. Usually, testing can be completed within a week.

How to Schedule:
Call or email us to set up a time to drop off your canner lid. We will notify you by phone when it has been tested and is ready for pickup.

Phone: 209-966-2417
Email: mrygiol@ucanr.edu


Does My Canner Need Testing?

Please Note: Generally, only Presto brands and some older pressure canners need their dial gauges tested. Other brands (like All-American) are "weighted gauge" canners; their dial is only used to indicate when pressure drops to zero and does not require calibration.

Tip: Convert Your Presto Canner

You can easily convert your dial-gauge Presto pressure canner to a weighted gauge system by swapping out the standard deadweight for a 3-piece weighted regulator. This allows you to use the canner as a weighted gauge canner, meaning you won't need to worry about annual dial testing.

View the Presto 3-Piece Regulator Part