Is your Air Pressure Gauge Accurate?
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- เผยแพร่เมื่อ 5 ก.ย. 2024
- Test and Calibrate Bourdon Tube Gauges.
The tire inflator gun I use: amzn.to/2fKmzV9
I like to calibrate them at a few pressures. Oiling is generally not a good idea but if you fell you must a very fine oil like wd40 is the most you would want to do.
Brass Tee 1/4npt: amzn.to/2fKs5XR
1/4npt to 1/8npt for smaller gauges: amzn.to/2giYbxP
1/8npt to 1/16npt for really small: amzn.to/2fKuGRV
Good to see this vid. Working in equipment calibration one tip I do have is to have one dial type guage sent for calibration but no need to pay for adjustment, just ask for a result sheet. Then put this unit aside as a reference unit to compare others against once a year or so.
Great tip.
I used this procedure to calibrate a Harbor Freight filler gauge to a Winters PFQ series industrial gauge spec'd to +/- 1.5%. It is very easy to do and highly recommended. The actual spreading or squeezing of the 'loop' is minimal so you have to be gentle with your tools.
Awesome.
i recently bought a Milton digital and compared it to my vintage US made Milton analog and the digital is spot on.
HEY! 65FORD IT WORKED! I had a brand new gauge about 8 lb. off and good for nothin'. Your video did the trick. Perfect. I've said this before on your channel... I wish we were neighbors. I've learned so many things from you. Very helpful. Thanks once again.
Thanks. That's awesome.
great 8 minutes I ever spent, we have a ton of gauges throughout the farm on all our poultry equipment and also in my shop...so now when I have a lazy snowy winter day I will head out to the turkey barns and the shop and spend a day checking all the gauges...it will also give me something to film...why didnt I think of this.....bet you and the Mrs were sitting around a cozy fire saying, "babe I need a TH-cam video topic" and she said: "while I am thinking of it... my tires on my car seem a little low"....You said "Thanks"
Hey Thanks.
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
4 years later still this video helped
Thx man
have a wonderful day
Great job!
Thanks for this great video. It is refreshing to hear the word "bourdon" gauge again outside of school. Interesting to note that the graduations of a particular gauge play an important role too. The less the graduations of the gauge, the more inaccuracy likely there is compared from one with more (200 psi vs 160psi).
Thanks, I'm glad you liked it.
Ive had them apart,but never thought about adjusting them. good info to have.
Seams they are always a little out.
Awesome...I've got a similar dial-type tire pressure gauge. It's nice to know I don't have to pitch it if it loses accuracy. Thanks Sixty-Five!!
I guess I'm rough on these, as they always seam to go out after a years use.
This video inspired me to calibrate my tire gauge/filler similar to what he is using. I calibrated my gauge to read the same value as my car's ('98 Corvette) TPMS reading. I have since ordered but not yet received a commercial grade 0-60psi oil filled mechanical gauge (Winters p/n PFQ803R1) that is spec'd to +/- 1.5% accuracy. I will use this new gauge as a reference and compare all my gauges to it. I don't plan on calibrating my five air compressor regulator gauges as tire inflation is more important to me than air tools. I have not been able to verify what the accuracy of the TPMS sensors but there should be an ASME standard for such devices, my guess is +/- 2-3% for automotive applications.
we get 10-20% speedo errors...why think the tire dongles are better ? I like your winters gauge idea best.
@@captlarry-3525speedo errors are mandatory. Car cannot show lower speed than you're going. They also need to consider that car can have different size wheels from the factory or the user can also install bigger wheels..
In some cars you can code the installed size or so. Many times car do know the exact speed or very close, but there's algorithm to add some.
For TPMS it's safety feature and I haven't looked exact spec but I believe it's close. Probably how the TPMS gets it's info (passive, active, etc) there's some difference in accuracy.
You're an extremely valuable internet video; could not make it without ya!
Thanks, I'm glad you liked it.
I used to do calibration, the way to do it is set at either mid range of the gauge it self to a known, or at a specific pressure range that will be used the most. a hydraulic dead weight pressure calibrator can be around $3,500.00,. even so the above still applies. your method is fine, only slight correction might be to set the gauges at the pressure used the most. I'm confident that your understanding of mechanical items that you could make one for yourself. It's simply a hydraulic fluid between a known floating dead weight pressurizing a cavity via a fixed diameter piston (1/8" to 1/4"), "no" 'o' rings, just oil fluid, some leakage is acceptable. cost of a hyd. jack pump, pipe fittings, then add known piston with cylinder with disk and known weights, calculations. regards
I've debated building a hydraulic dead weight pressure calibrator, but would need it so infrequently it wouldn't be viable. I have watched a few videos on them and looked at them online.
That was very useful! Thank you for posting. I never knew air gauges were adjustable. Pretty slick.
Another great video with some really good information!
Thanks.
Thanks for the info. It worked fine on my 20 year old gauge that was about 4 lb out. It saved my from having to send it from Australia to the US for service.
Thanks, I'm glad it was helpful.
Thanks Moe. Great video. My brother in law is an instrument tech . He gets to play with the expensive toys. The rest of us do what we can. Great stuff.
He would cringe at how I set these then.
Your method is more elegant than mine. My gauges are usually only off by a few psi, so I just bend the needle to calibrate.
Your method is more elegant than mine. My gauges are usually only off by a few psi, so I just bend the needle to calibrate.
Thanks for showing this, I knew they could be calibrated but I never thought it would be so simple. I guess the real trick is to have something that you know is accurate to work off of and you're set.
Thanks for watching.
A man with one watch knows exactly what time it is. A man with two watches has no ideas what time it is. A man with three watches can be reasonably certain what time it is.
Thanks again for all your videos,
Stay well
Ash from Scotland 🏴
Thanks Ash, I'm glad you like them. -Moe
This is an excellent explanation of the process. Thanks Moe!
Thanks for showing how these gauges are adjusted but would love to know where to find an affordable source.
nice! I never knew they could be adjusted. Sadly I just threw away several over the last 25 years when I found them to be off. Learn something new every day.
Thanks.
Good tip. What I have a problem with is my air hose connections, you did yours with one hand, mine takes 2 hands and a corner to push the connection in. The hose is an after market, I think Goodyear hose, thought it would good, but alas, it blows.
I've had troublesome air connections, but for the most part I've had great luck with the Home Depot Brass and Steel ones.
When I was younger, I asked my dad how he knows a gauge is accurate. He said he didn't and in fact, it'd be a good thing to use two gauges.
So then when he got a second gauge, and they didn't match each other, then I asked.... "Which one do we trust?"
And he said screw it, we'll just avg them, I'm not buying a third gauge.
And then he proceeded to grill me for the next hour on multiplication tables.
Thanks - got a fairly nice new gauge to keep in my shop (vs digging the one out of each car or my bike) and it's like 5-7psi low, this is much easier than playing roulette with exchanges. I don't need lab accuracy but I knew there had to be a better way to get within a PSI or so on checking tires.
Thanks, I'm glad you liked it.
It is very good instructions, Thanks
Thanks bro...mines back to working perfect!Saved me a trip to Canadian tire,and a few bucks $
Awesome. I'm glad you liked it.
I know a guy who does gauges & other instruments for a living & said gauges like them are only accurate between it's 10 o'clock & 2 o'clock positions so the 12 o'clock is the best spot to set them
I can see that being the case and it seams to coincide with what I've noticed.
Excellent video, full of relevant information and gets directly to the point!
Nice, didn't know of the ability to make the change. I would imagine the more they are loaded all the time in the case of a compressor the less accurate over time they will be?
Exactly. I think the metal has to fatigue and stretch over time.
Thanks for the great tip. Never thought it was that easy
Thanks, I'm glad you liked it.
I think I'm from the FIFTIES even just by mentioning this, but does there exist any more a "master gauge" at garages or tire dealers any more?
Not sure what to do with this new knowledge, but I am somehow glad to have it. Speaking of which, what do you know about generator heads? I know you've set the internet straight on sound reduction of the engines (what with all the muffler adding videos to nowhere), but I think a trouble shooting video would be a great thing to add. Beyond your video of adjusting the rpm's/frequency video I mean.
In my case, I lost one side of my 240 after a feedback brainfart from the mains because of throwing the main switch (for a second) before unplugging the gen. I first attempted a repair of the rectifier/brush holder, which didn't last, and then replaced it. Which worked yesterday for about 10 minutes use, until the power came back. But later after power went out again, I was back to 120...
I had also wired in a proper transfer switch and plug between the two uses yesterday. Which had me checking the new cable and such. Until finally checking at the actual outlets from the gen. But I still need to actually go through it to know that there's a problem. Was pouring rain yesterday, and we go months/years between needing the thing so...
But still, I think a video on the subject would be a great service to many...
For the most part it's generally the brushes or the AVR (automatic voltage regulator) that is the culprit. That is besides actually having shorted windings which is a death sentence. Shorted windings can be seen by there charred winding wireing.
I just repaired a one leg dead generator a few weeks ago. It was a very inexpensive Chinese model and it ended up with the wire disconnected in 3 places. Once broken by the brushes, next a loosened terminal on the circuit breaker, and finally disconnected at a 120v-240v transfer switch.
sixtyfiveford No AVR on this Troy Bilt 5550. Just a 4 diode rectifier with a single Varistor mounted onto the brush holder. Just need to pop the cover and check the windings with a ohms meter. The thing that confuses me is that it output the full 240v the first time, after replacing the rectifier/brushs. But I guess that could be a singed winding...
Since I post the first comment, I have seen the many different generator design variables. A video on the subject might not be as easy as I originally thought...
Great to know this thank you
Thanks for sharing your knowledge.
Thanks for tuning in.
Great video ! And to think I used to throw the bad ones away. Thanks again !
Thanks.
All my gauges agree at 35 PSI but some are way off at 80 PSI and I dont know which ones are good
I have never done it that way, I have a special tool that pops off the needle and I just put the need to zero with no pressure or at none pressure while in service.
That works. I find some gauges that when accurate at high pressure, still have tension on the zero post(if that makes sense).
Great tip Moe, THANKS!
Thanks.
Happy belated Thanksgiving and thank you for an awesome video, you read my mind.
Thanks.
Thanks for the info on this Moe. Just a couple of days ago I was doing a compression check on a Corvette engine and was using my 25 year old gauge. I don't suspect any issues wiith it but wondered how accurate it still was? I was getting 165-170 psi per cylinder so I wasn't worried about the results.
You never know. Sounds like a healthy engine.
most gauges are most accurate at the upper end of the scale and least accurate at the low end. this is why you dont want to measure 30 psi tires with a 300 psi gauge...and why a 100 psi gauge may not be the best either. That said, you can adjust a meter to be accurate in the range you use most say 30-45 psi... and live with however wierd it is on other parts of the scale. Another thing you can do is make a Calibration Chart... which could just be a magic marker note that say plus 9 psi at full scale.
That's amazing. Your a master Moe!
I can't bring myself to throw anything away.
Love the video..thumbs up! What do you think of using a digital pressure gauge as your control? My old Extech gauge says it's accurate to within +/- 1% of a kpa (or 1/7th of a PSI). I guess the digital gauges are also temperature compensated internally, so they are accurate regardless of operating environment.
I haven't had great luck with the digital pressure gauges. But I could have just got cheap ones.
Exactly what i have been looking for , . . . thank you
Hi Moe. Always good information. Thanks.
Thanks.
You should check how accurate gas station gauges are vs yours, since alot of people rely on them everyday
I'm sure they're off a little.
I have a gauge that’s coming out 60 for checking my tire pressure. So I should get a new one for sure.
Yeah, that's not good.
This is synonymous with a wearing a watch. If you have a watch, you always know what time it is. If you have two watches, you never know what time it is for certain. The more pressure gauges you have, the average is all you can go with. But you have no definite knowledge of the exact pressure. Thumbs Up for your video and info for adjusting bourdon tubes.
Thanks. As usual, I enjoyed the heck outta that video. I feel smarter too.
Thanks for tuning in.
Good to know. Thanks for posting
Yeah, thanks for tuning in.
Cool video, as always.
Thanks Chad.
I have one just like your favorite one but it's off at least 10 pounds guess I'll have to fix it know,, thanks for the tip..
That's exactly what forced me to tear into them.
Good tips
Thanks George.
I assume mine is right.. a bit more is not tooooo bad.. my tires are all old used tires anyway..
Great video, thanks
Thanks Miguel. -Moe
could you match them against the TPMS in your car for accuracy?
I don't see why not
nice job and great info.
Thanks for watching.
Ok, that gauge/filler that you said was a good one. Have you had any problem with the clip on chuck at the end? I have bought the kind that look like a regular fill chuck, but have an arm off to the side, that allows you to clip it to the tire stem, but that never works for more than 5 or 6 fillups. And even then, you have to hold it just right, or it just flips right off... I'm getting too old for this stuff. I can't just stay bent over for 5 minutes, while the truck tires fill up...
It won't hold itself onto the tire very well. I have to use one hand for the trigger and the other holds the clip on the valve.
Thank you. That is exactly the problem I am having with the air chucks I have now. Stooping and holding that, on the valve stem for the amount of time it takes to fill an RV or truck tire, is painful for the back, hips, and knees. I think I'm going to just try to adapt one from a cheapo bike pump, to my home compressor. At least when you flip the lever on those they actually STAY on the valve stem. :)
I know what you mean. When I change tires and am airing them up for the first time to seat the beam I use this tire chuck amzn.to/2hIza0H . It holds and allows me to step back out of the way until is done seating. I put a 1/8" npt pipe nipple on it and an air fitting. This style grips and holds on by itself.
That's exactly the chuck I am having problems with. You have to get it on there JUUUUST RIGHT. And if it moves the slightest bit when you are letting go of it, it pops right off the stem. Meaning you have to go back and put it back on there just exactly right again. And hope it doesn't move at all when you let go of it again... I'm looking at the cheapo pump style because when you flip the lever, you have a positive grip, and seal on the valve stem. www.amazon.com/Sunlite-Universal-Thumb-Lock-Hose/dp/B00629RMZE/ref=pd_sim_263_3?_encoding=UTF8&pd_rd_i=B00629RMZE&pd_rd_r=1FJG8EBQC8PA5WA58XQG&pd_rd_w=2vFNw&pd_rd_wg=Bevz1&psc=1&refRID=1FJG8EBQC8PA5WA58XQG
Also considering one of these, because it at least surrounds the valve stem threads, instead of getting a grip only on the lip of them: www.amazon.com/Pack-EPAuto-Straight-Lock-Inflator/dp/B017S44ARO/ref=sr_1_7?s=automotive&ie=UTF8&qid=1481793819&sr=1-7&keywords=air+chuck
By the way, I have gone through at least a dozen of those. Most seem to work well, right at first. After a while, you have to be careful to get it slid onto the valve as far as you can. That works for a while. Then, after a while, it just stops working at all.
I do that to , They are made in China most of the time these days and I want true pressure read every time ! great share .. Thumbs up Moe ..
Yeah, I have a few USA made ones that I cherish.
Right on !
Is a water pressure gauge the same as an air pressure gauge??? Great video.
All the ones I've opened up are the same.
@@sixtyfiveford Thanks. I thought that there might be a seal for the water pump gauge so water can't get into the dial. I didn't want to ruin the air gauge with water.
learn alot from your video, thank you!
Does temperature significantly affect gauge accuracy? The tube looks susceptible to thermal expansion and contraction.
I like the way you think. I was curious about this as well so I researched it a few weeks ago. Supposedly it throws it off .5% for every 20F in temp change. So if I set my gauge to 100psi on a 90F day it will read 1.5% lower on a 30F day(98.5psi)
thank you very much for share
Excellent video. Thank you very much. Problem solved
Glad it helped
I would never know my gauge was out, but my TPMS tells me it's 37 psi and my foot pump says 40. I don't know which one to believe.
TPMS is generally very accurate to within a single psi.
Thanks, good info.
Thanks for tuning in.
What do you do if the gauge isn't just off by a constant amount, but off by a percentage, like it's always showing 20% higher than it should?
Calibrating it at a determined pressure should make it accurate at any number.
Um, no. The calibration in this video is about moving the needle a constant amount. That isn't the same thing as changing the stiffness of the circular hollow part that expands to move the needle. I have a gauge that reads 0 psi perfectly, but reads 20% too high at any pressure. When the pressure is 20 psi, it reads 24 (4 psi difference). When the pressure is 100 psi, it reads 120 (20 psi difference). In all cases the percent error is the same, 20%. This means that the internal copper bellows (or whatever it's called) is flexing too much and moving the needle too far. Simply offsetting the needle position won't help.
The gauges will be off by a percentage, that's what I fix in the video. I'm not changing the needle position by bending the tab I'm changing the force that is applied exponentially. This changes the reading to be accurate. "Changing the needle position" would be simply pulling the needle off and putting it back on and would only be done is the reading was off by, say 10psi across the board. I don't do that in the video.
Pinching or expanding that little loop only offsets the needle by a constant amount, it doesn't change the stiffness of the bourdon tube. It doesn't change any force; there's no force on the needle, it simply follows a gear driven by the bourdon tube linkage. The only force in the gauge is the bourdon tube resisting the pressure, and that little loop won't change that resistance. It just allows you to move the needle without having to pull it off the shaft and reposition it. In the video, if you had snipped off the needle stop at the zero position, you'd find that yes, you've corrected the reading at a high pressure but also changed the position of "zero" for the gauge. My understanding of that loop is that it's intended for calibrating the zero setting. Of course, if there's a narrow range of pressure you're interested in measuring, then it makes sense to adjust that loop so the gauge reads correctly in that range of pressure, but it won't fix the percentage error of the bourdon tube.
@Anachronist no. Adjusting the loop changes the gain as he said. Offset is adjusted by moving the position of the needle on the shaft.
How do I calibrate my gauge from pressure canner?
Most pressure canners use a jiggler weight that will automatically regulate your pressure. The gauge is merely there so you know it's building/holding pressure.
So rad! Thank you:)
I'm glad you liked it.
thanks
Thanks for tuning in.
It's a shame how many I have thrown away over the years and that's all I had to do to fix them
Thanks for watching.
thanks for the vid. got the gas tank in the 65 f100 yay. but what kind of tractor is that you have small one with the attachments ? thanks!
I have a 1952 Ferguson TO30 that I run a wood chipper and log splitter off of in some of my videos.
what about the small lawn and garden one you have with a front end loader?
That is my 1984 MTD 998 Garden Tractor. It has a front end loader and rear 3 point hitch.
Cool
Thanks.
You da man!!
Hopefully it was helpful
Use a sealed tank itll give you better accuracy
Ive never messed with the one i have, its one that came attached to a double cylinder foot pump, so its cheap.
I would undo the two scale fixing screws and see if i could get enough play to rotate it a tiny bit lol, im a chicken, i dont want to slip and damage the bourdon tube LOL.
They're pretty reliable on stationary items.
What's your take on digital gauges? Can you calibrate them?
I've bought a basic cheap digital one years ago and it was horrible. I'm sure there are nice ones though. I tore it apart and saw no way to adjust it.
Is that screw on the back of the gauge a zero adjust or a maximum pressure adjust? I question your gauge adjustment procedures.
The screws on the back just hold the gauge assembly into the housing. Most gauges don't come with any adjustment options, so expanding/contracting the metal at the bend is the best way to adjust it!
Best video ;)
Thanks.
next time could you please do a close up when showing how the gauge works
NAIS!
Thanks.
Thank you for that DIY.
Thanks, I'm glad you liked it.
Now show us how to calibrate a digital pressure gauge. Lol
How can you use a slew of inaccurate gauges to combine and use as your reference gauge? Don't be so cheap and buy a good analog gauge like the drag racers use.
You keep costing me money...
Is there anything this guy doesn't know how to fix!?
Only one way to find out. I'll try to fix everything. Thanks Man.
Your method is very flawed. You assume that gauges that read the same must be accurate. You also claim that you know one of your gauges is accurate. How do you know that? Did you test it with a super-expensive industry standard calibration tester like you mentioned? I doubt it. And, even if you did, how long ago was that?
I'm not saying your method has no value. In fact, it has excellent value and is useful. But you can't KNOW that any of your gauges are accurate unless you tested it against a standard recently. Here's an example of the point I'm making: Not long ago, I tested 8 gauges that I have including a couple stick gauges, three mechanical dial gauges and a couple digital guages. Most of them read about the same with the exception of one dial gauge that read 5 pounds over what most of the others read. Being a retired engineer, I actually had access to a machine to test the gauges or, rather, I know someone who has access to such a machine. It turns out that almost all of the guages were off by a couple pounds. Suprisingly, the cheap stick gauges were the most accurate with the exception of one that was off a few pounds.
The moral of the story is that comparing gauge readings is fine and useful but you cannot claim that they are accurate just because they read the same. The best you can say is you THINK they are probably accurate because they are reading the same.
You have a great point! However, when you compare multiple gauges, it becomes less and less likely that all of them are inaccurate, and more and more likely that they are accurate. They do the same thing with science experiments... take the average of several measurements to get better certainty of the result
worthless video. You are measuring against an unknown.
thanks
Thanks for tuning in.