Not really answering your question but I wouldn't rely on the pressure gauge on the inflator. I use something like this from Halfords. Reasonably quick but noisy.
http://www.halfords.com/webapp/wcs/s...egoryId_255241
And always double check pressure with this (which is excellent)
http://www.amazon.co.uk/RACE-PROFESS.../dp/B000VZ8S26