Open the Preferences dialog from the bottom left window, to find a section to set up the measure device or spectrophotometer:
Choose the Device from the list given, in order to read a color directly on textile or on paper.
You also have the option to make readings with UV filter.
You will have to calibrate the white reference only the first time.
Connect the Spectrophotometer and place the cursor on a color chip and double-click at the same time you press the ⌘+ Alt key (on a Mac) or the Ctrl+Alt key (on a PC) place the reader in a white space and press Absolute.
The readings can be Simple or Triple. When you select Simple, the device will read the color reference directly on the color.
The Triple option makes three readings and provides an average value based on them.