It's tricky. You must have the dipstick right way round, as fluid almost always drags up one side of the tube and wipes off on the stick the next time. Best way is to pull the dipstick, then wait a minute or so after wiping it off to allow the fluid dragged up the side of the tube to drain back down.
Re-instert stick, allow to stand for 20 sec or so for the fluid to "climb" up, then pull and read BOTH sides. The one with a line of fluid perpendicular to the side of the stick is the level. May be on the marked side, may not. That's the reason for getting the stick right way round -- if the marked side is covered with fluid and the other side indicates level, you must rotate it 180 degrees when you put it back in. I never remember, just read the side where the fluid level is.
Complicating the issue is that some dipsticks are marked for both hot and cold fill -- cold mark is always lower than the hot mark.
I'd rather read the dipstick six times filling up that burning the tranny up!
By the way, did you ever fix the thump in the rear of your 190?
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!