How to disassemble, repair and calibrate an air pressure gauge

How does an air pressure gauge work?
How to take apart an air pressure gauge?
Is your pressure gauge miscalibrated? How to re-calibrate?
I try to answer these questions in this short video.
-if the bezel is pressure fit, simply pry it off little by little.
-take out the two screws from the back of the gauge
-remove the mechanism from the case
-bend the calibrating piece with pliers gently until you get the needle to point to 0 at rest, but not rest with any force on the stop if there is one.
-compare to a known good gauge and readjust until satisfied.
NOTE: your gauge might not have a calibration element. After I took this video, I took apart my second gauge, and I realized that that one does not have that calibration link, but a straight link instead. So what I did with that one is I bent the big semicircular element - the Bourdon tube - inwards, right near the block it's attached to. It's key that you bend right near the block, otherwise the dial will keep moving further and further from 0. You need to do this gently, but you can generally bend it back the other way if you've gone too far. You keep gently bending it in either direction until you get the calibration where you want it.
You can get more information than you ever wanted to know about these Bourdon gauges on Wikipedia: en.wikipedia.org/wiki/Pressur...
See my related video on how an air compressor works: • How does an air compre...

[@briansd2772]

This is the kind of content KZbin needs! You just saved me $60 on buying a replacement gauge. Thank you sir.

[@kreygscott]

Outstanding video. Yesterday I accidentally dropped my gauge which began reading 20psi below the actual reading. After watching this video I was able to fix it which now works perfectly. Thanks mate. New subscriber now!

[@zMuddaFkka]

Fell asleep twice listening to this hypnotist... 😑

[@brandon7722]

🤣🤣

[@kimgunn1644]

Hey, did you know you can click mouse ? slide it any where skip all sh*t ? lots of people don't even know this trick ? you can watch movie at start ?if don't think any good ? slide the mouse down to next to end ? see how it even ends to ? lol ? i do it all the time hope maybe this help you and friends to if didn't know it ?

[@jamesdorpinghaus3294]

Thank you for making this video. The screws came out of the reading plate and it was loose. Wasn't sure if it was safe to take the front off without damaging it but now it's fixed.

[@chasep1903]

1:03 - 2:34 Disassembly 3:00 - 3:50 How a Gauge Works 4:30 - 6:00 How To Set To Zero Again 6:30 - 7:00 How To Calibrate With a Tire

[@raagtop363]

MANY thanks. Your video helped me repair a TireTek gauge that would not "zero". I probably didn't have the optimal tools but with a just screwdriver and small needle-nose pliers I was able to do the job. The bezel actually popped off easily with a flat screwdriver. There's a slot at the top of the gauge that allows this access.

[@K-G-S_66]

So i went and bought a classic vintage tire gauge and was the only one available and needed adjustment so i got a good deal 3 years later still this video helped Thx man have a wonderful day

[@duncanblackwell958]

Excellent. Thanks. I've been using a separate guage every time I checked my tyre pressures. Now I can just use the one on the inflator 👍

[@fluxcapacitr121]

Awesome. Thank you. I’m tuning up an old air compressor to sell and the tank gauge was off 15 psi. I knew there was a way to fix it that didn’t involve me driving to harbor freight and buying another cheap gauge.

[@kv4atv]

I use a T air fitting connected to the pressure. Connect a good knows gauge to one side and the one you're working on to the other. You can now set the one you're working on to read the same as the know good reading gauge.

[@Slangevar333]

Thank you for your video it helped me make 2 gages that were seized up functional again and now they work perfectly

[@NareshRamchan]

Excellent video, very informative. I was able to repair a similar gauge with your help. Thanks

[@LouisEvangelista007]

Nice video! Have to try this on one of my gauges. Glad I found this segment! Thank you!!

[@makaveli2tt]

Thank you. This video helped me out with my gauge. It's fixed!

[@nibornoreht]

Thanks! Valuable info, now I can fix my gauge!

[@phillipmcguffie1183]

The Pressure gauge linearity is more than likely not messed up. Through use, the gauge will fall off of its zero. The best way to bring this gauge in is to take it to mid scale with pressure or liquid. You will want a known good gauge as your reference. Once you have the reference gauge at 75 psi (the mid scale of your 150 gauge under test) pull the needle on the uut and reset it at 75 psi. When you remove the pressure, the gauge should return to zero and be back in its linearity. The specifications for pressure gauges are normally at nominal points. 20% 50% 70% and 90%. for 20%, you are looking at a 2% spec. At 50%, 1%. At 70%, 1% and at 90%, 2%. Once you have tested these points, you will know your pressure gauge is within specifications and ready to go. A bourdon tube bend will only be done when the gauge has a crimped on gauge cover and you can not access the gauge needle from the front. You will take the gauge to mid scale and try to bend the tube from the top hole of the gauge. This works most of the time but takes an amount of tinker time to nail down how to bend it. I do it with a flat head screwdriver and looking at the front of the gauge, put the driver in the top and down the left side. this allows for the best results. anyhow, if you can get some new techniques from the information i have provided, you will be in good shape. Bending that u shape on the arm is not a good idea. The bending only weakens the metal and brass is already a soft metal. pulling the needle using a needle puller is the best method but can be done with a pair of needle nose pliers and a pick if done carefully. anyhow, best of luck to you.

[@steelddd]

Phillip McGuffie thanks for the insights! Might try those next time I have a gauge to fix.

[@phillipmcguffie1183]

No problem. I work in calibration and this is how we handle gauges that fail to meet the manufacturer specifications. Good thing to look into if you do enough of these is to make a pressure comparison jig. something with a reservoir to handle the supply to the reference gauge and the unit under test. Makes gauge calibration a snap. We use denatured alcohol as our solution. it dries fast and rids the gauge of contamination quite well.

[@rdg515]

Phillip McGuffie You should do a video and link it here

[@phillipmcguffie1183]

@@rdg515 I could do that if it would help. Sorry for the late response. I was not aware that this response was even made. lol

[@grizzalo6117]

Hi. Wouldn't pushing the needle against the tube put excess pressure on the gear teeth and loosen the gauge causing a wobbly needle reading? Under normal operating, the gears only have to move the needle.

[@jorgetirado1345]

Very helpful your explanation. Good job!!!!

[@raullorsch538]

Thank you so much, it worked with my pressure gauge perfectly!

[@zubairahmed]

Thanks, my gauge was over, I didn't have the loopy bit on top, so I tightened a semi circular metal below which did the job

[@justinreid8851]

AwSome video sir on the recal of my old gauge. Many 👌👌👍👍 onntge knowledge you have.

[@MrDunk66]

I just took my vac/pressure gauge apart because the the needle was off zero. Simply by gently pressing on the bourdon tube, the toothed lever that rotates the dial moved to its end location (probably jumped of the dial axle), the need shaft rotated and reset itself zero all by itself. The dial is now on zero and the dial moving mechanism is centred. Thanks for the video 👍

[@madhavanravikumar3329]

Great, will try tomorrow.. 😅

[@MattSeals]

Many thanks, this video content is very practical.

[@ninjageezer6802]

Spot on worked a treat

[@03pad73]

Very helpful video!

[@brandon7722]

Great video!!

[@DLHFarms]

Thanks just what I needed

[@vanrijn1669]

I had to put my clock back to slow down enough to grasp the slow talk. And...the Um, um um, um. Thanks for posting though.

[@Zickcermacity]

"Whatever you want to call it"... 4:01 - Bourdon Tube.

[@jiatan815]

thanks for the video

[@rosjja]

Thanks

[@AffanShaikh-fw1hp]

What are the various tools required for pressure measurement system

[@matt4398]

Drink a big coffee before the next video

[@glenwagaman9103]

After what seems like 7 hours I tapped out, it's dragging on forever.

[@kessthegamer5305]

I speed it up to 1.25x

[@TheRobo46]

Thanks, used snap ring pliers , little by little to zero out...

[@hectorortega9131]

Good video, But Man, this guy Talks Slow!..

[@mafosa8519]

All you did was zero out the needle. Still needs to be pressure calibrated with the right equipment. Still a good share Larry

[@luross2057]

Is that possible and economical

[@kimgunn1644]

great your skills are, i know i never would had fine that fix ? even i work on Airplanes for a living over 15 years to ?? i was a long show learning but i got it at end ? not sure everyone would understand it to unless worked around stuff like this to cars planes trucks ! you get the picture thank's ? but worth it to ? lol ?

[@pelagic022]

Thank you 😊

[@ManojKumar-ub7wz]

Thank you

[@gb8164]

Hi friend! Will this work as well for a water pressure gauge. I have a hydrotherapy machine that is the sole driver of my current biz. It just broke. No clue how to fix it, and the manufacturer Dotolo is no longer functioning. Any advice or help?

[@steelddd]

The principle should be the same. But if it "broke", you might have bigger issues (still, doesn't hurt to take it apart and see what's up in there. You should be able to find the right gauge with right thread, right size, right pressure and right fluid at a supply shop. Measuring the thread is the tough part, but a hardware store might be able to help you.

[@JLXC90]

Hi, I have a +2psi on my gauge. Does it mean I just need to open up the U slightly?

[@steelddd]

Can't remember which way is which, but it shouldn't be hard to see.

[@tuxnoel]

The dial becomes inaccurate once the Cu pipe starts corroding. Better to use digital ones. I had supposedly good quality one stored for one year unused. After that it became unusable.

[@dani121121]

that's a bourdon tube pressure gauge, the thing with the teeth is a quadrant gear and it drives a pinion.

[@worcesterexchange554]

Nice to have someone who knows what they are talking about - thanks.

[@bangdingow1414]

I always thought the screws in the back were for calibrating the gauge. 😆

[@kumarar745]

Nice,useful way of talk is k

[@TiberiusStorm]

The zero adjust is actually calibrated by simply removing the needle and putting it back at zero. There's also an Adjustable Link for the span and a linearity adjust which is often a screw.

[@steelddd]

Shaine MacDonald thanks for the tips! Do needles come off and on easily by hand or need a special tool?

[@ghenrysr002]

How do you get the boot off?

[@steelddd]

Just pry it off usually.

[@blackbirdwisconsin]

Is there a good way to get the face off?

[@steelddd]

Apparently you can just pull the hands off and then the face comes off

[@fourbypete]

I gave a thumbs up because I found out what I needed to know eventually. You should write out what you are going to say because Uuuuuuuum your video Uuuuuum took longer Uuuuuuum than it needed to.

[@cHVF]

I took a nap and my gauge is still not calibrated. good news bad news type thing.

[@twoweeledsoto6072]

I have two older Accugauge that are both out of calibration. Yet both start at zero still. Just an FYI , that it doesn't have to be off zero.

[@steelddd]

Do they have a stop at 0? Because then zero doesn't mean anything.

[@twoweeledsoto6072]

@@steelddd yes, both have material stops at zero. I understand zero means nothing because of that, but I would've thought because of that stop, it would've resulted in too LOW a reading of our of calibration? But I'm sure one is reading about 7-8 lbs HIGH at ,,,,,. GIANT OOPS! I think I see the problem now. Because it shows 30 and is actually close to 38. Yep, you're correct. I've gotta get it to register higher, while still starting at zero! Thanks. Sometimes it takes me a little longer. 😂😂😂

[@vvvspqr]

Hahahahha soooo simple now Thank you thank you thank you

[@subramoniams9850]

I was scratching my head how to bring back the needle of my analog gauge back to zero. Thanks for the video. You have another gauge there with which you said you checked the repaired gauge. How do you open that one? There are no screws on those kind. Mine looks the same and there is no way to open it. Should I knock off the pin jutting out on the sides?

[@steelddd]

I haven't taken one of those apart yet. Let us know if you find the trick.

[@steelddd]

I finally took a look at it. By the pins it looks like it's probably not meant to be disassembled past the bezel. But I see there are some screws on a piece that retains the needle. Maybe you can take that off, pull off the needle and reset it. Maybe those screws retain the faceplate as well. Sorry, don't feel like ripping mine apart :)

[@PHAESTOS64]

um... um... um... um... it seem to me dude that it's you that needs calibration the most

[@JulietteNiner]

Just loosen those two screws in front my man. Twist the bezel then tighten while holding the inflator on a known air pressure.

[@rodneybrand8521]

Why didn't you have it connected to air pressure so you could demonstrait how the gage works ??? And show the ajustment??? Just replace it ... What happened to the gage was too much pressure for the gage's range...just saying. Cheers 🍻🍻🍻🍻🇺🇸🇺🇸🇺🇸

[@5556665012008]

The gauge should read 1 bar NOT zero when not pressurised, zero would be a vacuum, 1 bar is atmospheric pressure

[@steelddd]

Not on most gauges I've seen in the US. It's just a question of definitions. If you wanna just measure pressure above atmospheric, you can start at 0, as these gauges are marked.

[@noelk6606]

Not quick. Just make one that gets to the point still thanks for the video

[@dang2341]

@ Steelddd, Would you be interested in making a prototype that would create a new category in an industry where you are a specialist of something? If your open for a project let's discuss it. Thank you! I just add you as a connection in youtube.

[@worcesterexchange554]

Really annoying that he is holding the camera with one hand and trying to take a gauge apart with another. Just get a little camera tripod and have a video that we can watch please.

[@jimme8499]

Doesn't show how to calibrate at all !

[@johnmilner7603]

Buy a cheap tripod from China, lots on eBay. Stop suffering. Ah, Um.... stop it.

[@davidomeara4704]

This guy has no clue how to calculate a bourdon gauge. No property trained technician would do this

[@steelddd]

very true I just winged it

[@DrMaserati]

The basic information in the video is good. But the video is horrible. I would be embarrassed to post a video like this.

[@vibinm7279]

He make one minute video to 7 minutes... Bullshit😠😠😠