Where and when were guns and cannon on replacement aircraft sighted in?

[Snautzer]

2 types: Kompensierscheibe and Kompensierwaage.

Taken from LEMB, Piet Bouma:

A "Kompensierscheibe" (plural: Kompensierscheiben) is a large wooden disc that was reinforced by a wooden construction below the disc itself in a (sometimes even almost 2 meter deep) foundation. The entire disc could be moved around by hand power or by a motor located inside the foundation.
(When a "Kompensierscheibe" was not only used for calibrating the on-board aircraft compass, but also for calibrating the "Radio-Peilgerät" (for Radionavigation), it was referred to as a "Navigationsdrehscheibe" - hence the abbreviation ND in the type mentioned above...

The second group is the group referred to as a "Kompensierwaage" a word I have only come across once in a book in which the photograph of the Ju88 at St. André (see above) was portrayed. This is a circular concrete platform onto which they placed a wooden construction that could be pivoted around the point in the middle of the main landing gear. It is not completely sure if the aircraft was pivoted around this main landing gear or that the main landing gear was on a wooden disc as well; personally I don't think so - but I don't have proof for that... We are sure from the remains of such a Kompensierwaage at Grimbergen, Belgium that there was a wooden disc construction in the middle of it (probably a bit smaller than 2 meters). I think it carried the beginning of the wooden construction, so that it could pivot easily.