Most floor pumps have a fairly accurate pressuge gauge mounted on the front. That's what I use.
If I have a flat or slow leak while out riding, I pump up the tire with the frame pump and do the "feel" test. If it feels about as firm as when pumped up by the floor pump I'm happy.
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The Lord is merciful and gracious, slow to anger and abounding in steadfast love. - Psalm 103:8
I am a cyclist. I am not the fastest or the fittest. But I will get to where I'm going with a smile on my face.