Roger Breton wrote:
I can't help but marvel at the technical prowess of your device driver for the i1pro. How on earth are you able to extract down to 3nm data out of thisdevice?
Well since X-Rite/Gretag don't provide Linux drivers for the i1pro, and they're existing drivers don't have a compatible license for distribution with a GNU licensed package, I've had to figure out how to understand how the instrument works at the USB level. Luckily it has a reasonably well organized interface, but what you get is the 1 dimensional CCD sensor output from the instrument, plus the calibration information stored in its EEPROM. (this is typical of how many low cost instruments communicate.) This calibration information basically describes how to resample the CCD data from the physical sampling of approximately 3.5nm (approximate because it's not calibrated) spacing to the calibrated 10mn spacing. By interpolating this information, and reformulating it using a sync filter template, I can create a resampling into a 3.333nm spacing report. The resolving power isn't really 3.333nm, but it does seem to make a difference for spiky emissive spectra. Since I don't have access to a suitable reference instrument, I'm not sure though, whether it really improves it's accuracy or not. Graeme Gill.