Tyre pressure gauge

[jedrinck]

Which tire pressure gauge is recommendable? I have a F Renault car which I drive for fun occasionally and the recommended pressures are in the range of 1,45 to 1,65 bar (maybe 21 to 24 psi). I have compared the Longacre analog gauge I used so far with a couple of others and the differences were up to 0,3 bar (4,3 psi) which sounds like a lot to me. Are digital gauges any good? How can you find out if a gauge is calibrated accurately?

[Adam43]

For a true calibration it would need to be checked every so often. Against a known - not easy to achieve. I suppose you could send it back to the manufacturer?

IMHO there is no benefit of a digital gauge over an analogue one. Just make sure your analogue one has a nice clear display and read it correctly (no parallax). As with most things in life, you get what you pay for.

Get out one that works in the region you want - no need for 100psi for you.

Overall I worry little about calibration, I set by pressures on my tyre gauge. And I know what I like on my gauge. In some ways it doesn't really matter if it is absolutely right, I just crave consistency. So stick to the same gauge when you settle on one. I risk the danger of inconsistency if I lose it, but I could over come this by having two good ones that I know the difference between.

[GORDON STREETER]

Any gauge as long as it has an accurate repeatability. I've had the same analogue one for 30 odd years and it has always been very accurate if I compare it with anything new, and think of the money in batteries I've saved

[ubrben]

If money's less of an issue this is the best product out there. Used by pretty much the whole of F1, DTM, etc:

http://m-a-horne.co.uk/products/gauges.php

I paid approx. £201 INC VAT for one last week.

Ben

[Andrei]

Well, now I use a proffesional one like the one showed by ubrben. For me, it has the advantage of readability, temperature compensation and the possibility to sent it back for calibration (I do it once a year).
Before, I have used a analog type from FLAIG. Very good one, it has some analogic form of calibration - the dial may be rotated to have 0 bar - and beeing in Germany, I have sent the gauge back for calibration a couple of time.
For the times where I have not been payed for engineering, the FLAIG gauge was good enough and it was also good enough for amateur racing.
Price difference 35€ for FLAIG, 400 € the other one.

[ubrben]

Originally Posted by Andrei

Well, now I use a proffesional one like the one showed by ubrben. For me, it has the advantage of readability, temperature compensation and the possibility to sent it back for calibration (I do it once a year).
Before, I have used a analog type from FLAIG. Very good one, it has some analogic form of calibration - the dial may be rotated to have 0 bar - and beeing in Germany, I have sent the gauge back for calibration a couple of time.
For the times where I have not been payed for engineering, the FLAIG gauge was good enough and it was also good enough for amateur racing.
Price difference 35€ for FLAIG, 400 € the other one.

Good point Andrei, I'd forgotten to mention the temperature compensation.

Ben

[jedrinck]

Thanks for the Flaig advice Andrei, I just ordered a gauge from them. Very nice people and close to where I live. "Des isch kei Probläm, schigge ma ihne uff Rechnung."
By the way, what do you mean by temperature compensation? Could you dial in something like 1,5 bar at 80 degrees and the gauge tells you the pressure you need to set with the ambient temperature so you get what you want once the tires get warmer?

[Andrei]

Glad to be able to help you.
About temperature compensation - when adjusting pressure in hot tyres, the temperature of air entering the gauge is altering the properties of the membrane. A digital one has straing gages, those are temperature compensated and you do not have this problem. I only saw once that my digital gace was showing 0.01 bar when taking no pressure. Outside was over 40° hot and I have forgotten it in the sun. but 0.01 bar is 0.5% of the 2 bar I want, so it is no problem.
With the analogical one, I have seen no more then 0.2 bar temp drift but that was a lttle bit to much on the racetrack. Of course, If you know that, it is not such a problem. I just have had the opportunity to buy the good one in a tensioned moment. Otherwise, I would use the FLAIG one also now.

[jedrinck]

I see, that never occured to me. So with air from a hot tire, it will read more than the actual pressure?