sbslider

Looking for a tire pressure gauge that I can use on schrader and presta valves, go as high as 100 psi and measure somewhat accurately as low as 5 psi. This will get used for bikes, cars, and home RO filter system. prefer a dial gauge (no batteries), but the Topeak D2 SmartGauge seems to be highly regarded. Another I looked at was the Planet Bike analog gauge, but several reviewers said it did not work well with presta valves.

Weigh in please!! thanks.

rydabent

IMHO The best thing to have is a good quality floor pump with a built in guage at home. Now if you are touring you will need a good pressure guage. BTW dont let the I can tell what my tire pressure is with in 2 pounds types miss lead you. They will tell you you dont need a guage.

Looigi

I know of no gauge that works well or properly with presta valves and skinny bike tires. Too much air is let out of the tire. You best determine the pressure in a bike tire by reading the pump gauge as air is going into the tire.

Spld cyclist

It's a bother, but I use one of those screw-on presta to schrader adaptors if I need to check tire pressure on a presta tube. I agree that using the gauge on a pump is better, but this works.

sbslider

I have a pump with a gauge, and I like the pump. Not sure how accurate the gauge is though. Also it is a hassle to carry around and measure the air in my car tires, and again I don't know how accurate it is. and again for my RO system.

sbslider

I suppose I could live with that for my bike, as in general I would use the pump gauge. Just nice to periodically compare that with another gauge to see if it is still accurate. That is assuming the second gauge is always accurate, and there are no guarantees there . . .

FBinNY 

Generally, accuracy of any measuring instrument is proportional to the scale. A gauge made to read pressures to 100psi or higher isn't going to be accurate at less than 10psi.

Just as you wouldn't use a yardstick to measure things smaller than 1/4", or a bathroom scale as a postal scale, you cannot use a 150psi gauge to measure 5psi and expect any accuracy.

pierce

indeed, for my cars, I use a pencil stick gauge that reads 0-50psi, and for my shraeder valved bikes, I have one that reads 0-100psi. skinny presta tires, I've always gone by the feel of the skinny tire and the tone it makes when I thump it with a finger.

FBinNY 

Gauges are most accurate at the center of the scale, so 0-50psi makes sense for a car whose tires typically inflate to about 30psi. OTOH, 100psi is a pinch for most bike tires since we tend to ride at 60-95psi or even 100+. When I made bike tire gauges I scaled them for 0-160psi. That gave then an accuracy of ±2psi between 60 and 110psi.

sbslider

Perhaps what you are saying makes sense, but coming from an electronics background I have not problem using my hand held Digital Volt Meter to measure 0.2V or 350V. It is very accurate measuring either. Don't see why other measurement devices can not be accurate across the range as well. For 5psi, I am hoping for 10-20% or so accuracy, it is not rocket science putting air in an RO tank bladder. For my car, I would like a fairly accurate gauge, hopefully to a 1 PSI or better. For my bike, the difference between 85 and 90 PSI is not a big deal. I just don't want a reading of 90 PSI to really be 70 PSI. Again, not rocket science. If there are not gauges that are this good in an single product then I guess I am out of luck.

FBinNY 

Perhaps what you are saying makes sense, but coming from an electronics background I have not problem using my hand held Digital Volt Meter to measure 0.2V or 350V. It is very accurate measuring either.

While a meter might (that's for purposes of discussions only) be somewhat accuracy for both small and large readings, the relevance isn't. Most gauges and meter are built to an accuracy based on the overall scale, ie, ±1% of the scale, so a 200psi gauge is accurate to ±2psi. That's fine at 100psi where it's only 2%, however even if it were equally accurate at 5psi, the error is now ±40%. So when we talk of accuracy in measurement it's both a question of precision and the relevance of the error.

As for the electronic meter, read the fine print, and you'll see the problem of using a large scale for small readings. My digital volt meter has a switch which selects a scale of LT 2v, LT20v, LT200v and GT200v. I use the smallest scale greater than what I expect toe voltage to be. If in doubt, start at max, and work my way down so I don't blow the internal fuse.

Bill Kapaun

At what temperature?

sbslider

exactly

Bill Kapaun

Just because you can READ a digital meter accurately, doesn't mean what you read is accurate.
The DISPLAY has a % of accuracy +/- 1 digit PLUS the error of the measuring circuitry.

sbslider

So it seems like if my 100psi gauge can resolve to 1psi, then my needs are met.

Still looking for a specific gauge recommendation . . . .

cyclist2000

I use a Meiser presta valve gauge for my tires. I don't know of any pressure gauges that fit both presta and schrader. This is the one I have in my touring bag and I find that I don't lose much air when checking the tires.

sbslider

Ok, now I regret bringing up the meter analogy. My hand held meter is autoranging. I don't manually change the range. 1% accuracy when I measure 0.2V is 1%, and 1% accuracy when I measure 350V is 1%. It does bring up the point that an electronic readout can resolve to higher precision than a mechanical dial readout. Whether or not either display is accurate is a different matter.

I certainly did not intend this thread to be a discussion of measurement accuracy, but perhaps that is good as it helped me to quantify what I am looking for. I think my last post stated it best.

Can you recommend a 100psi gauge that can resolve 1psi, and works with either schrader or presta valves? No need for further discussion on all the nuances of making measurements. No need to suggest I buy a floor pump, I have one with a gauge already. If you wonder why I want a second gauge, don't bother posting, or at least don't be put off when I don't respond to your post.

FBinNY 

Sort of, if you're willing that a reading at 1psi is off by as much as 2, ie from below zero to 3psi. That's assuming it's even accurate at that range, which I only conceded for the purposes of the example. The fact is that gauge accurace falls off to either side of the center of the scale (most makers consider the middle third to be the working range) so a gauge built to read to 1% (of scale) accuracy center scale, will typically only be accurate to 2-3% at the ends of the scale, so at 5psi, a 0-100psi gauge may read anything from 2-8psi, making it kind of useless for those purposes. But that's up to you.

For brands, both Planet bike, and Topeak build decent gauges, and probably buy the piezo-electric element from the same guy, so either will be fine. More important is probably the quality of fit and seal at the valve, so not much air is lost putting the gauge on and off.

sbslider

Thanks for the comment FB. I echo your concern/though about finding a gauge that the quality of fit and seal is what is really going to help at least give the gauge a chance to be accurate. So recommendations of gauges that do this well are welcome. If need be, I will use the shrader adapter for my presta valves on my bike to minimize this air loss for the occasions I need to use the gauge for my bike tires.

fietsbob

Ive come across Pencil Stick High pressure shrader valve gages in the past..

being Metal, they last almost forever .. and dont take up as much room as dial Gages
in the jersey pocket.

sbslider

I purchased the SKS airchecker gauge, battery powered yes but I will give it a whirl.

rydabent

Any guage that will be accurate within 5 lbs should be quite ok. Having one that is down to 1lbs plus or minus is way beyond what is needed.

cyclist2000

I had one of these from 40 years ago, found it in my tool box a few years ago and it didnt work, I assumed that aluminum corrosion was causing added resistance. maybe dipping it in ammonia would fix it up. But what I meant to say was mine didn't last forever, yet.

JanMM

+1 Really like my presta accugage. Insignificant air loss on removal and a very nice pressure bleed button.
They make a variety of styles and pressure ranges. Get one presta and one schrader!

FBinNY 

We tried to help, and I even suggested 2 digital gauges, both of which are PV/SV. What else do you want to know?