If I understand you correctly - You have the same Logical product but according to the type of product you need to hold seperate measurement types.
How about this approach with an Instancing Table
Not Tried this particular way myself so it's just an idea
You will need to make full use of the transform statement in Access to view the data - & panic if you ever upgrade to SQL Server which has not got an equivalent statement
"Everything should be made as simple as possible, but not simpler." - Albert Einstein
"Everything should be made as complex as possible, so I look Cleverer." - Application Developer