Instrument standardization where the Bottom of Scale (0% line) and Top of Scale (100% line) is set by first blocking the light path and taking a reading and then clearing the light, except for a blank solution and taking a reading. This must be done at least once for every 8 hours of use, or at any user selectable interval less than 8 hours.
Instrument calibration can only be done by trained HunterLab service technicians at our Reston, VA service center. This entails using the emmission lines of Hg and Kr or lasers such as HeNe or CdNe to set the wavelength mapping of the detector and then ND filter and Gray scale tiles to check the Linearity and then colored filters and tiles to check the color measurement accuracy of the instrument. Instrument calibration verification testing is recommended every 12 to 15 months. If any test produces a failure then returning the instrument to HunterLab for calibration is the required action.