[ksa8907]

My job deals directly with accurate temperature and pressure measurement. I think what you're after is repeatability and not accuracy. It doesn't matter that your tire is exactly 40.000 psig, it is more important that the tires are approximately the same pressure.

The transducers we use in high volume are around $1000 and error is +/- 0.4% of full scale, we buy 0-30, 0-100, and 0-600. The transducers we use for critical places are about $1500 and are +/- 0.05% of full scale and are 0-2300 psig.

I'll drive the point home, ignore accuracy and go for repeatability in this case.

Also, the reason they are so expensive is because they are high quality electronic transducers. So how good is that $5 digital tire guage?

+/- 2% of full scale on a gauge that goes up to 100 psig would be 2psig. So instead of 40 it could be anywhere from 38 to 42 with no way for you to know.