I’ve been using those little pencil type gauges for a while and I know they’re less than ideal. Got a shock when I check tyre pressures yesterday, one of my gauges said the tyre was 36psi, the other 32!
I’m wary of the digital ones, do they actually work well? I’m told the ‘gauge on the end of a hose’ type are most accurate. Any useful web links?
Cheers! 
All I can say is don’t get the Hein Gericke one, it only lasted around six months and loses pressure very quickly. The ones at the end of the tube are more stable. I am also on the lookout for a decent one, tried a digital one and it was crap.
I’ve got one of these:
http://www.toolsbypost.com/product.php?id=159&category=
And it seems to work fine and is well built.
Not very portable though.
I have this one:
Costs 22,95 EUR, fits under your seat, Made in Germany, and according to the little paper that came with it it’s personally inspected by some bloke named Sch… something and accurate to ±1%. It has a neat little button you can push when you take the pressure, it then takes your reading and zeroes when you push it again. It’s quite heavy, feels solid and seems well made and it would probably hurt if I bonked you in the noggin with it. What’s great also is it doesn’t need batteries since it’s an analog piece of kit. It’s under my seat now next to the mini-can of chain lube. 
My theory is that it doesn’t matter what sort of gauge you get, as long as the gauge itself doesn’t get less accurate over time.
If mine’s consistently, say, 0.1bar too high, then over time I’ll learn to set my pressure so that my gauge shows 2.3 bar when I actually only need 2.2 bar. I don’t really care what that is in “real” settings, as long as it’s the correct thing for my tyres on my bike.
If the gauge were to become progressively less accurate over time, I would notice it either because I’d feel it when riding or because over time I’d keep noticing a growing difference between the gauge on the air m/c and my gauge.
In any case, how would you know that a gauge is inaccurate? To do that, you’d need a gauge that you KNEW was 100% correct to benchmark it against. I don’t have access to one of those.
FWIW I use a Motrax pocket sized one, battery operated, from HG, cost about a fiver (?) some years ago. Works fine for me.
I have a collection of digital and manual gauges, all but one of which give different readings that aren’t same as my Honda dealer’s expensive machine – the most consistently accurate gauge of all is the non-digital one actually on my footpump:
I hope that helps.
I use a little Motrax digital guage. I’m not sure how accurate it is, but it’s far better than the guage on your average petrol station forecourt.
They’re all inaccurate and without a very expensive lab machine to check them against, you’ll not know how far wrong they are.
If you can find an old “Motometer” metal cased mecahanical dial one in good order, you’ll not be that far out. Probably.
The last time I bought a Chinese “Motometer” copy (the real thing had been stolen) I borrowed 5 or 6 guages from all over the place. Used them all to check one tyre and averaged the results.
My cheap Chinese thing was 0.05 Bar off average. I call that good enough.
