ALTANA Spectro-Guide Sphere Gloss Manual - Manual (Page 21)

20
Calibrate
6. Calibrate
Three calibration standards are supplied with the
measuring instrument. These include a black
standard and a white standard for calibration of the
instrument, as well as a green test standard. To
perform the gloss calibration, the instrument is
further equipped with a high-gloss standard. All
standards are manufactured from highly stable
materials. When performing calibration, it is
especially important to ensure that:
1. The standard is clean.
2. The instrument lies completely within the
diaphragm on the standard.
3. You set the instrument on the standard as
shown in the illustration.
Open the lid of the standard. Position the measuring
instrument so that the display points in the direction
of the open lid and the front edge of the instrument
is parallel to the edge of the lid. This ensures that
you will always perform the calibration under the
same conditions.
The measurement results are very stable over time.
With proper handling, it is possible to obtain
calibration intervals of up to 3 months.
Recalibration is necessary when the optical
components become dirty.
You can determine the need for recalibration of the
instrument at any time by performing a
measurement with the green test standard. The
values for the test standard are stored in the
measuring instrument. When you measure the
green standard with the “chk green” option from the
calibration menu, you receive a message indicating
whether recalibration is necessary.
You should also carry out this test immediately after
calibration, in order to determine whether it was
performed correctly.
Fig. 5 Calibration