ALLDOS Diagraphm Metering / Dosing Pump M 201-222 110V Prodos II

Description

Brand: ALLDOS Inc.
Model #: M 201222
Spec: 110V / 60Hz
Prodos II
Made in Germany
DOM: 12/86
From a client that I am liquidating there excess equip.   Hard to say if this is used or unused.
Testing: I am not a user of this type of equipment so limited testing.  Plugged in and pushed left "power" button.  When the top dial was at a number below 30, it was seconds between pumps, then in 30-60 range it was a short period between pumps and then when 60-100 it pumped very often.  I don't know what the bottom dial is for but if you can give me directions I can test that too.  I also don't have anything to plug into the back side "probe" jack so maybe that is what the other dial is used to control.  Either way it looks in very nice condition and is of German quality.
It does not come with anything other than the metering pump itself.
I can't find any specs online since it is older.