968 Spectrophotometer Operation Manual ***discontinued ... - X-Rite

Calibrating to a White Standard . . . continued4) Measure the WHITE patch on thestandard. You must hold the unitdepressed until all five readingshave been completed.> You must set the unit on thestandard so that the maximumamount of the bottom rubber padof the shoe resides on thestandard (refer to Section 4.1)."CAL READING 1 OF 5" thru "CALREADING 5 OF 5" is displayed; then"CALIBRATION UPDATED." Theprocedure is finalized and theunit returns back to main menu.> During the Cal Reading, the readhead must remain down andstable or an error message mayoccur.> If "PLEASE WAIT XX (1-30)SECONDS" is displayed duringcalibration, continue to hold readhead down until calibrationreadings are over. This will onlyoccur if the calibration procedureis performed within 30 seconds ofa previous measurement.> If "READ ZEROREFLECTANCE" is displayedafter reading the white spot, goto step 5. This will only occur ifthe calibration values for zeroreflectance have drifted.WHITECALIBRATIONUPDATEDCAL READING5 OF 5CAL READING4 OF 5CAL READING3 OF 5CAL READING2 OF 5CAL READING1 OF 5THE FOLLOWING STEPS (5 & 6) ARE ONLY NECESSARY IF YOU WANT TO MEASUREZERO REFLECTANCE, CHANGE SPECTRAL VALUES, or CHANGE APERTURE SIZE.5) Steps 5a - 5d are only necessary if "READ ZERO REFLECTANCE" is displayed,you want to manually activate Zero Reflectance Measurement, or YOU WANT TOCHANGE APERTURE SIZE.Zero Reflectance is defined as, "measuring air with no ambient light".This can be accomplished by holding the unit depressed (take a reading) in adark room. In some cases, it is possible to just take a reading under a desk withno direct light.To manually activate zero reflectance measurement or you want tochange aperture size, see next page.33