i think mostly because the workshop airpump use the same compressor which also power the air wrench..
due to the force require by air wrench, i guess the default pressure of the compressor is actually higher than usual tyre pressure within 30PSI....

so the pomen only "agak2" your tyre pressure whenever he fill-in the air...most of the time they will just fill bit by bit and knock/press your tyre to guess if it reach the acceptable pressure....

I'm referring to motorcycle workshop...Yes, pressure gauge/meter at compressor important to monitor output pressure supplied by the compressor... cos torque wrench/air wrench usually require 90PSI to operate...not an issue if they use separate line and regulator for air pump nozzle and air wrench...

but most pomen i saw at motorcycle workshop just quickly swap (pull & plug) the air pump nozzle and torque wrench using the same line from the compressor ...dont think they can simply regulate the air pressure by doing that...

For car workshop mostly they will double check using pressure gauge plug onto your tyre valve..but i never saw motorcycle pomen done it...

This post has been edited by silverbolt143: Aug 6 2012, 01:53 AM