8250A Optical Power Meter Operation Manual
2.1.1 Function Description
2-3
10. DOWN
Changes the measurement range down when RANGE is set to
MANUAL.
11. UP
Changes the measurement range up when RANGE is set to MAN-
UAL.
12. RATIO/dBr
Displays the ratio (relative value) of each successive measured
power to the power which is measured when “W” is displayed and
[RATIO/dBr]
is pressed. No unit is displayed. This function is
canceled by re-pressing
[RATIO/dBr]
.
If the measured power in units of “W” exists in the over-range or
the range of 10 counts or less, the RATIO calculation cannot be
set to ON even when
[RATIO/dBr]
is pressed.
Also displays the relative value (dB) of each successive measured
power to the power which is measured when “dBm” is displayed
and
[RATIO/dBr]
is pressed. “dBr” is displayed in unit. This
function is canceled by re-pressing
[RATIO/dBr]
.
If the measured power in units of “dBm” exists in the over-range
or under-range, the dBr calculation cannot be set to ON.
13. MAX
The MAX indicator is lit and the maximum measurement value is
held and displayed in the MAX HOLD state by pressing
[MAX]
.
This function is canceled by re-pressing
[MAX]
.
The maximum value, which is displayed and held in the MAX
HOLD state, is initialized when the measurement range, wave-
length, display unit, CF value, or calibration wavelength is
changed or the calculation ON or OFF, or ZERO is executed.
14. SM
Performs the moving average calculation (smoothing) of the mea-
sured value and can reduce noise.
The SM indicator is lit and the smoothing calculation is started by
pressing the
[SM]
key. While the SM indicator blinks, the mea-
surement does not reach the set number of times that smoothing is
performed.
This function can be canceled by re-pressing the
[SM]
key.
If the measurement range, wavelength, CF value, or calibration
wavelength is changed or ZERO is executed while smoothing is
performed, the SM indicator blinks again until the measurement
reaches to the set number of times because the smoothing is ini-
tialized. Set the number of times that smoothing is performed in
MENU. The initial value is set to 10. Smoothing cannot be
started, if the number of times that smoothing is performed is set
to 0 or 1.
15. MENU(ENTER)
Sets to the MENU mode. For more information on the operation,
refer to 3.1, “Menu Map.”
The MENU items are changed and then the MENU mode exits by
re-pressing this key in the MENU mode.
For more information on the operation, refer to 3.1, “Menu Map.”
16. PREV
Returns the MENU item to the previous item in the MENU mode.
For more information on the operation, refer to 3.1, “Menu Map.”
17. NEXT
Progresses the MENU item to the next item in the MENU mode.
For more information on the operation, refer to 3.1, “Menu Map.”
