On Aug 20, 2015, at 7:55 AM, Liane May <LMay@xrite.com> wrote:
It is always a good idea to perform an i1Diagnostics test, but be sure to use the latest version 4.1.1. This version can trigger an extended calibration of the device if a drift in the white reflectance measurement is detected. If you believe a device turns out to deliver questionable measurements, even if it passes an i1Diagnostics test, please contact our support directly for additional help.
I agree, it sounds like recertification will likely fix things up for you (cumbersome as it might be in the UK). Also, I’m curious if you’ve tried calibrating using a different (known good) instrument’s white patch as an experiment to see if it makes a difference. I also hesitate to mention, as you have very likely checked, but for others on the list, carefully inspecting the filter / lens of the instrument and removing paper dust can make a huge difference. The i1 Pro gen 1 instruments were particularly good at filling the little filter cavity with paper dust. Finally, we also offer an inexpensive service with Maxwell (good for the life of the instrument) to periodically verify instruments using any color reference you like. You can trend the device and get email notifications for failures, etc. It doesn’t require the use of Maxwell for other things. regards, Steve