Convert from crith to zentner [Germany]

Unit Definition (crith)
The crith is a unit of mass sometimes used in the physics and chemistry of gases. The crith is equal to the mass of a liter of hydrogen at standard temperature (0.01°C) and pressure (1 atmosphere); this is about 89.885 milligrams. The name comes from an ancient Greek word for a barleycorn.

Unit Definition (zentner [Germany])
The zentner is a traditional German unit of weight or mass, comparable to the traditional quintal and to the English hundredweight. Similar units were used in Scandinavia. Originally the zentner was equal to 100 pfund, or German pounds. 100 pfund varied from 110 to as much as 120 pounds avoirdupois (49.9-54.4 kilograms), depending on the market. After the introduction of the metric system in Germany, the zentner was redefined to equal to exactly 50 kilograms, which is about 110.231 pounds. In English, the zentner is commonly spelled centner.