Except for some particular cases where the tool is clearly defective, the errors that come up in calibrating the spectrophotometer are essentially due to a dirty, damaged or wrong standard (typically a small white or green ceramic plate) or to a wrong placement of the tool by reading the standard.
In the case of COLOR MATCH EASY both the WHITE and the GREEN standards are included in a small box that is provided with the spectrophotometer.
Be sure that the serial number indicated on the sidewall of each standard matches the same serial number as that of the spectrophotometer. Otherwise, you cannot calibrate the tool, because it cannot recognise the standard.
Place the tool accurately on the requested standard (typically the GREEN standard, but, if it has been a while since the last calibration, it may ask for the WHITE one). Check whether the tool direction is right and the measurement field is placed on the specific compartment in order to guarantee a perfect planarity of the surfaces.
Push the side button of the tool or click on the icon on the display to acquire the calibration standard.
To facilitate the alignment, on both the tool and the standards box there are some arrows that indicate the right placement of the tool in relation to the standard (see below).
If you still have some doubts, please remember that our Software & Instruments Assistance Department (email@example.com) is at your disposal. They can also help you, if necessary, managing the instrument repair.