I've seen your plots too, I like to experiment myself.
My UV Fluorescence 380nm - 730nm measurements proove the oposite, perhaps my instrument is different I have original Gretag-Macbeth not X-rite.
The i1Pro sucessfuly reads from 380 to 730, on non fluorescent sample there is flat line graph, no erroneous data.
The samples are measured using special adapter, precission power supply, UV light source etc.
Data is constant and repeatable.
The right attitude. However if you send a message here it might help others if you specify the paper measured, the surface your target is measured on.
To what do you get opposite results? To what I wrote in my message here or to the paper white spectral plots I publish?
My two years old Eye 1 Basic measures from 380 to 730 NM. The hardware is the same as the Eye 1 Pro. The UV-Cut version Eye 1 measures from 400 to 730 NM according Robin Myers: http://rmimaging.com/information/Chromaxion_Issue_1.pdf
I got the impression from your first message that you measured with two spectrometers: a UV-Cut Eye 1 Pro and an iSis, the last used for a UV-Cut and a UV enabled measurement. I tried to explain that for both UV-Cut measurements the plot below 400Nm or 430 NM is a software extrapolation based on the measurement above that value, more guesswork than measured data.
Your second message seems to imply that you use a normal Eye 1 Pro so one that measures into UV. Or you assume that the file with measurements from your UV-Cut spectrometer that shows reflection data from 380 to 730 NM is enough evidence that the meter measures below 400 NM. That is not correct, see Robin Myers comments in the link above. If it did measure below 400 NM it would not be a UV-Cut instrument. Could you make it clear which instrument you used?
Where you mention a special adapter, precision power supply, UV light source etc I guess you refer to the iSis. I am not aware of that kind of parts for the Eye 1 Pro.
It would not surprise me if a spectral plot of an iSis in UV mode differed below say 420 NM to a spectral plot of a normal Eye 1 Pro that also measures into UV. The light source of the iSis is a UV LED as I understand it and the Eye 1 Pro is using a tungsten light source. Differences in the UV spectral output of the lamps will trigger (different) OBAs differently. So did my Spectrocam with a Xenon flash. The standards for spectrometers have not been that tight. Manufacturers like Gretag Macbeth and X-Rite will massage the measurements that they are not conflicting too much and deliver usable data to create profiles that can work. 1000-5000 $ instruments are a blend of science, manufacturer and user experience plus compromises that give practical results for 90% of the cases where a 100K $ instrument may deliver 99% practical results.
Met vriendelijke groet, Ernst
Dinkla Grafische Techniek