This might be a case where it depends what you want to do with the data and no obvious clear answer at the outset.  An example to compare it to would be street address.  In most cases the number and street would be in the same field.  But that might not give someone who sells houses the needed granularity.  In this case there would be one field for the street, and another for the address.  Two tables rather than columns are being discussed, but the intent is the same.  It seems to me that generally these would be combined.  But if the requirement is to take certain measurements that this combination would make more difficult, then better to separate.