fix: improve unit recognition

test/test_unit.py

@@ -15,6 +15,9 @@ def test_basic_units_html():
         "0,75 kW": "0,75 kW",
         "33 A": "33 A",
         "1 Ah": "1 Ah",  # Ah can be a tricky case if the RegEx is wrong, as A might match before Ah, thus rendering the output with an "A" unit
+        "10 A/mm²": "10 A/mm²",
+        "DL9MJ": "DL9MJ",  # Ensure other strings, like callsings, aren‘t mistaken for units. ;)
+        "Ein Satz mit 200 V.": "Ein Satz mit 200 V.",  # Support units before sentence ends.
     }
 
     for input, output in assertions.items():