I'm a schrader user
related: when I check my tire pressure with a hand held gauge, a little air escapes. so when I'm deflating the tires on my Jeep, when I get close to the pressure I want, I use the gauge repeatedly to get it perfect. meaning the more I check the pressure, the lower it goes. because bike tires are so low in volume, checking the pressure may change the pressure more than one wants. so when you get it where you want it, leave it alone