You might give this link a try:
Air dryer requirements
For over a year, my primary water clearing was to have an electronic drain on the compressor tank. It would open for one second, four times per day. I had multiple water traps but they never caught anything. But, something I learned is that if the air is too warm [and it will be warm coming out of the compressor], the water traps do not work. You have to cool the air down before they work.
If you really want to dry the air and you are having issues, what @Midnight_machinist suggests will tell you where you are at with moisture. Recharging the desiccant beads are the most economical you can get but it will take extra time and effort. But…it will give you time to evaluate your situation without plunging a lot of money into it.