Techkon SpectroDens Manual page 62

If a dot % patch in black is measured close
to the SC_k target value it will be displayed
automatically.
The HR_k is detected automatically as well.
The arrows show the recommended density
adjustment.
The detection of HC_k works in the same
way.
If the measured value matches to the target
value no adjustments are necessary.
Page 62 Manual TECHKON SpectroDens Chapter 2 – Measurement functions