iQC Verification Green Check Tile Failure

Each instrument is sent out with a green ceramic tile. Before it leaves the standards lab, the green tile is read, and the CIE 1976 LAB values are published on the certificate. The purpose of the check tile job is to read the green tile every day and compare the current values to the values from when the instrument was new. This is done to ensure that the instrument is not drifting an unacceptable amount over time.

There is an option in Color iControl to have a check tile job open when the program starts.

If the green tile reads numerically different from the initial reading, the check tile job will fail. Two possible reasons are:

- The tile is not clean. Please clean the tile.

- The temperature of the room is substantially different than the standards lab (72). For every degree Celsius that a tile changes it gives a 0.08 shift in CIE 1976 delta E*.