When you say the not interchangeable I assume you mean they are not functionally interchangeable. It seems that physically the nose pieces (my term, not x-rite's term) can be interchanged. Hence, the UV filter nose piece fits on a body I own that is not matched to the UV filter. By the way, it would be interested to know what the differences in the bodies are (UV-filter or not.) I suspect they are hardware identical, but differ in the ROM contents. -------------------------------------------- On Mon, 10/6/14, Graeme Gill <graeme@xxxxxxxxxxxxx> wrote: Subject: [argyllcms] Re: i1 pro - eye one pro - spotread error To: argyllcms@xxxxxxxxxxxxx Date: Monday, October 6, 2014, 6:18 PM Alan Rockwood (Redacted sender alanrockwood2000@xxxxxxxxx for DMARC) wrote: > More information: I found an image of the bottom of an i1 Pro. The label on the main > unit indicated UV filter, whereas mine does not. > > It's becoming more and more clear that my unit has a mismatched filter. That seems like the case, so the white calibration error was legitimate. > I contacted the person who sold me the instrument, and he said he would see if he has > the correct filter (no UV filter) for my unit. They were never interchangeable on the i1pro, since it doesn't have multiple calibrations (unlike the Spectrolino). Graeme Gill.