Dial gauge or weighted gauge, and the yearly job one creates
Sources last opened 2026-08-26.
The short version
Both kinds of gauge are recommended, and neither is safer than the other when it is working. The decision is about what each one asks of you afterwards.
A weighted gauge controls pressure by mechanical fact and needs neither watching during processing nor checking for accuracy [F-3.4]. A dial gauge reads more finely, and has to be checked for accuracy before use each year, because a gauge that reads high causes under-processing [F-3.5].
That annual check is the only recurring obligation in home canning, and it is the thing worth knowing before you buy rather than after. Extension services test dial gauges, usually free or nearly so, and one manufacturer tests four brands free by post [F-3.6].
Two ways of holding a pressure
A pressure canner has to sit at a stated pressure for a stated time. There are two mechanisms for making that happen, and they are less similar than they look.
A weighted gauge is a machined weight that sits over the vent port. Steam builds until it lifts the weight, some escapes, the weight drops back. The pressure is whatever it takes to lift that weight, and that figure is a property of the object. The guide's summary: weighted-gauge models control pressure precisely and need neither watching during processing nor checking for accuracy [F-3.4].
A dial gauge is an instrument. It measures the pressure and displays it, and you regulate by adjusting the heat. It is more informative and finer-grained, and it can be wrong, which is the entire difference.
Both are recommended. Neither is a compromise. What you are actually choosing between is a machine that tells you nothing and cannot mislead you, and a machine that tells you everything and might.
The job one of them creates
Check dial gauges for accuracy before use each year [F-3.5]. That is the sentence, and it is the only annual maintenance obligation in this hobby.
Three things about it are worth spelling out.
It is not conditional on anything. Not on the canner being old, not on the gauge looking odd, not on a jar having failed. Drift is invisible.
The consequence has a direction. A gauge reading high causes under-processing and may result in unsafe food; a gauge reading low over-processes [F-3.5]. Both are worth fixing. Only one is a safety matter.
Two pounds is the line. Pressure adjustments can be made if the gauge reads up to 2 pounds high or low; gauges more than two pounds out are replaced [F-3.5]. So a failed test is not automatically a new canner. It is often a new figure to run at, given to you by the person who tested it.
A weighted gauge creates none of this. It needs no accuracy check [F-3.4], and the reason is that there is nothing in it to drift.
What a weighted gauge gives up
Precision at altitude, in exactly one place.
Weighted gauges cannot correct precisely for higher altitudes, so above 1,000 feet they are operated at 10 instead of 5, or 15 instead of 10, PSI [F-3.4]. Whole steps, because the weight only comes in whole steps.
That is why weighted-gauge process tables carry two altitude columns and dial-gauge tables carry four [F-4.2]. It is not that one machine is more carefully specified than the other. It is that one of them can be dialled and the other can only be stepped.
Practically, the coarse step means more heat than the recipe strictly needed. That costs texture in delicate foods and costs nothing else. And it has one clear advantage at the top of the range: above 8,000 feet the dial-gauge tables run out entirely, while the weighted-gauge column is open-ended [F-4.2]. There is a page on that: above 8,000 feet.
Getting a dial gauge tested
This is a local question with a national answer sitting behind it, and there is no point in this site pretending otherwise.
Locally. County and state Extension services test dial gauges — that is the standard route, it is usually free or close to it, and many run clinics before the preserving season. Find yours through the Ask Extension link above, and ask what they need: some want the whole lid, some just the gauge.
By post. National Presto Industries tests National, Magic Seal, Maid of Honor and Presto gauges free of charge, at ATTN: Gauge Testing, 3925 N Hastings Way, Eau Claire, WI 54703 [F-3.6]. That covers a large share of the dial gauges in American kitchens, and it is a legitimate reason to link to a manufacturer.
If your canner is an All American. Those are made by Wisconsin Aluminum Foundry, and on them the weighted gauge is what regulates while the dial is reference-only [F-3.6]. Your pressure is being held by the weight.
I am not going to build a directory of county testing dates here, because the Extension services that run those clinics already publish them and they are the ones who know when the next one is. Linking to them is not modesty. It is the only version of this that stays correct.
The honest summary
If you are buying: either gauge is fine, and the weighted one asks nothing of you afterwards.
If you own a dial gauge: it needs testing before use each year [F-3.5], and if it has been longer than that, this week is a good time to send it.
If you own a weighted gauge: check the vent port is clear before every load, and remember that above 1,000 feet you step up rather than fine-tune [F-3.4].
And whichever you have, the figure you run at comes from the tested source for the specific food, not from the canner's manual and not from here. What you actually need to buy covers the rest of the equipment question.
What a weighted gauge does, and the one thing it cannot do
Weighted-gauge models exhaust tiny amounts of air and steam each time their gauge rocks or jiggles during processing. They control pressure precisely and need neither watching during processing nor checking for accuracy… The single disadvantage of weighted-gauge canners is that they cannot correct precisely for higher altitudes. At altitudes above 1,000 feet, they must be operated at canner pressures of 10 instead of 5, or 15 instead of 10, PSI.
USDA Complete Guide to Home Canning, 2015 revision, p. 1-20
The link above opens the document itself, so a printed page number leads somewhere. What this document is, and who maintains it.
Opened and read by this site on 2026-08-26.
A weighted gauge is not a measuring instrument. It is a weight sitting on a port, and steam escapes when the pressure underneath it is enough to lift it. The pressure is set by physics rather than by a reading, which is why the guide says it needs no accuracy check.
The rocking or jiggling is the regulation happening. It is also, incidentally, a continuous audible signal that pressure is being held — a dial gauge gives you nothing unless you look at it.
The disadvantage is bluntly stated and it is real. A weight comes in fixed steps, so altitude compensation moves you a whole step up rather than a precise amount. Above 1,000 feet, a process calling for 5 is run at 10, and one calling for 10 is run at 15. That is more heat than the recipe strictly requires, which costs texture and costs nothing else.
Note what the guide does not say here. It does not say a weighted gauge is less accurate. It says it cannot correct precisely, and then it tells you the coarse correction to use instead.
The dial gauge, the annual check, and the two-pound line
Check dial gauges for accuracy before use each year. Gauges that read high cause under-processing and may result in unsafe food. Low readings cause over-processing. Pressure adjustments can be made if the gauge reads up to 2 pounds high or low. Replace gauges that differ by more than 2 pounds. Every pound of pressure is very important to the temperature needed…
USDA Complete Guide to Home Canning, 2015 revision, p. 1-20
The link above opens the document itself, so a printed page number leads somewhere. What this document is, and who maintains it.
Opened and read by this site on 2026-08-26.
Four instructions in five sentences, and they are not interchangeable.
Check it every year, before use. Not when it looks wrong. A dial gauge drifts without any visible sign, and there is nothing about its appearance or its behaviour on the stove that tells you it has.
The two errors are not equal. A gauge reading high means the canner is at less pressure than you think, so the food gets less heat than the process called for. That is the direction that matters. A gauge reading low over-processes, which costs quality.
Within two pounds, you correct. Beyond two pounds, you replace. A gauge that tests two pounds high is not broken, it is offset, and the tester will tell you what to run instead. A gauge more than two pounds out is not correctable and the guide says to replace it.
And the last clause is the reason for all of it. Every pound of pressure matters because pressure is standing in for temperature, and the relationship between them is fixed. A pound is not a rounding error here; it is a few degrees, and the whole process was calculated at the degrees.
The Extension version, and where to send a gauge
Pressure canners with a dial gauge should be tested annually to ensure accuracy and safety.
Dial gauges that read more than two pounds difference (high or low) during testing must be replaced.
Pressure canners with a weighted gauge do not require testing.
University of Minnesota Extension, testing dial pressure canner gauges, live
Opened and read by this site on 2026-08-26.
Extension restates the guide's rule in three flat sentences, and adds the part the guide has no way to give you: who actually does the testing.
Per the same page, National Presto Industries tests National, Magic Seal, Maid of Honor and Presto gauges free by post — send the gauge, or the canner lid with the gauge attached, to National Presto Industries, ATTN: Gauge Testing, 3925 N Hastings Way, Eau Claire, WI 54703 [F-3.6].
The page also notes that All American canners are made by Wisconsin Aluminum Foundry, and that on those it is the weighted gauge that regulates — the dial is there for reference [F-3.6]. If that is your canner, the dial is information, not the control, and the weight is what is holding your pressure.
For every other brand, your county or state Extension service is the place to ask. Many run seasonal testing clinics; some test year-round by appointment. That is a local answer and this site will not pretend to hold it for every county — the link below is where to start.
What people ask next
Which one would you buy?
A weighted gauge, if the choice were free of other considerations, and this is a judgement rather than a finding. My reason is that it removes a recurring task that has to be remembered every year, and things that have to be remembered every year eventually are not. The tested guidance rates both, so this is preference, not safety.
The case for a dial gauge is genuine too: it shows you what is happening continuously, it is the gauge the finer altitude bands were written for, and if you already own one there is no reason to replace it. Get it tested and use it.
My canner has a dial and a weight on it. Which one am I supposed to follow?
It depends on the canner, and the manual is the authority on your specific machine. On All American canners the weight is the regulator and the dial is reference-only [F-3.6]. On some Presto canners a weighted regulator can be fitted to a canner that also has a dial. The general rule is that whichever component is physically limiting the pressure is the one you are operating on, and that is the one whose figure you follow.
My gauge reads zero when the canner is cold. Doesn't that prove it is fine?
No. A gauge can rest correctly at zero and still be wrong under pressure, which is the range you actually care about. That is why the guide asks for an accuracy check before use each year rather than a look at the needle [F-3.5]. The test is done against a known pressure, which is not something a kitchen can produce.
How long does testing take, and what does it cost?
Locally, usually minutes and usually free or a nominal fee — but it varies by county and this site will not quote a price it has not checked in your area. By post, National Presto tests four named brands at no charge, and the turnaround is however long the post takes each way [F-3.6]. Send the gauge well before the season starts rather than the week you want to can.
Presto is a manufacturer. Why link to them at all?
Because the gauge-testing service is a real public service and there is no non-commercial equivalent by post [F-3.6]. Worth being precise about what that endorses: Presto is a manufacturer, not a tested source. Its published canning tables happen to match the USDA guide exactly, and the page does not cite USDA anywhere [F-15.2]. Use them for the testing service. Take your processing figures from the tested source.
I have not tested my dial gauge in years. Is everything I canned unsafe?
It is unknown, which is a different thing, and unknown in one direction only — a gauge that has drifted high means those jars had less heat than the process called for [F-3.5]. Get the gauge tested now, before the next batch. If it comes back accurate, you have your answer. If it comes back reading high, treat the affected low-acid jars as questionable rather than as fine, and decide with that in front of you.
Read these yourself
University of Minnesota Extension — Testing dial pressure canner gauges
extension.umn.edu
NCHFP — Recommended canners
nchfp.uga.edu
USDA Complete Guide to Home Canning, 2015 revision
nchfp.uga.edu
Ask Extension — find your state or county Extension service
ask.extension.org
National Presto Industries — canning information and gauge testing
gopresto.com