How to use a Viptronic VIPDENS 120 desitometer

[EdoNork]

I have not a clue how to use it, it's similar to this:

 

[ic-racer]

By the looks of it, I wonder if it reads the strip in a slot. I have one densitometer that reads like that, but it requires the patches to be placed a certain position on the strip. Something a common sensitometer and step wedge can't accomplish easily.