Furuno FCV-30 - Manual (Page 80)

3. CHANGING SETTINGS
3-12
8. Click Target sphere calibration.
9. In the Target sphere TS box, use ◄ or ► to set the TS value (fixed value) of the target
sphere.
10. Click the Start measurement button.
The TS value of the calibration sphere inside the area marker is calculated and is
displayed in the Setting value box.
11. If necessary you may fine tune the found value.
12. Click the OK button to finish.