Sorry Ale, I should have been clearer.
Yes, I carefully place the wiper arm tips on the windscreen to gauge the adjustment needed, but don't run the wipers or you'll scratch the screen. To be as accurate as possible, you really need to set the arm tips parallel to the screen at the distance they sit normally from the screen with the blades in place, but this is difficult to judge accurately. This is why you may need to make final small adjustments when you try them.
Hope that it works for you, good luck, MZ.
