Anritsu MS9740B - Page 97

3.1 Calibrating Before Measurement
3-7
3
Measurement
To set automatic calibration:
This function suppresses level and wavelength errors by automatically
calibrating the offset in the optical module after measuring the ambient
temperature and air pressure.
Use this function as per the following procedures.
1. Press
F8
to display Cal on the horizontal function keys.
2. Press
F2 Cal
.
3. Press
f7 More 1/2
.
4. Press
f2 Auto Cal
to set On.
Subsequently, the level is calibrated automatically after the ambient
temperature or pressure changes.
During automatic calibration, the message “Auto Cal in progress” is
displayed.
Note:
This auto-calibration function suppresses measurement errors
caused by changes in ambient temperature and pressure.
Wavelength calibration may need to be executed manually.
If remote control is used, this function turns Off.
To set Auto Offset adjustment:
When Auto Offset is to On and a Single (Repeat) sweep is executed,
sweeping is executed when offset is calibrated to adjust the offset when
VBW is switched.
When Auto Offset is set to Off and a Single (Repeat) sweep is executed,
measurement can be performed at high speed because sweeping is
performed without executing offset calibration when VBW is switched.
Usually, the offset level changes with temperature. To obtain the
highest-accuracy measurement results, we recommend performing offset
calibration once every 2 to 3 hours. Execute Zero Cal at this time.
1. Press
F8
to display Cal on the horizontal function keys.
2. Press
F2 Cal
.
3. Press
f7 More 1/2
.
4. Press
f3 Auto Offset
to set On.
When this function is turned off, the message “Auto Offset Off” displays
on the screen.