From a procedures section in a document:
Transfer 1.5 g bovine milk powder into a 200 ml volumetric beaker.
Is it common practice to omit of in construction of the kind
1.5 g (of) bovine milk powder
I have the impression that it is, but I'm not 100% sure. Maybe there's some book describing this condensed style of writing, and this omission of prepositions is mentioned there, but I haven't found a clear mention by googling.
Neither did I find any discussions of this on language-related websites.