7-33
IM AQ1210-01EN
Using the Utility Feature
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App
Index
Explanation
Wavelength
The photodetector of the optical power checker has wavelength sensitivity characteristics. The
photodetector corrects the sensitivity according to the set wavelength and measures optical power
more accurately. Select the wavelength from the following:
1310 nm, 1490 nm, 1550 nm, 1625 nm, 1650 nm
Unit
Set the optical power display unit from the following.
dB (absolute value), dBm (absolute value), W (absolute value)
• Unit W is preceded by a prefix m (10
‒3
),
µ
(10
‒6
), n (10
‒9
), or p (10
‒12
).
• The following relation holds between the absolute display unit dBm and W.
P
dBm
= 10×log (P
w
×10
3
)
P
dBm
: optical power (unit dBm), P
w
: optical power (unit W)
Reference Value
You can set a reference value and display the relative measured values (the differences from the
reference value).
• When you tap the DREF soft key, the displayed measured value becomes the reference value.
From this point, relative values will be displayed. The unit changes to dB.
• When you tap the DREF soft key or set the unit to dB, the Reference box appears on the power
meter screen.
• You can set the reference value in the Reference box. The range is –80 dBm to 40 dBm.
• When you set the unit to dBm or W, the Reference box disappears, and the absolute measured
values will be displayed.
Threshold
You can set upper and lower threshold values and determine whether or not the measured values fall
within them.
• The range for upper and lower threshold values is –80 dBm to 40 dBm. The upper limit must be
greater than the lower limit.
• If the measured values are less than or equal to the upper limit and greater than or equal to the
lower limit, the corresponding bar graph is displayed in green.
• If the measured values exceeds the upper limit or fall below the lower limit, the corresponding bar
graph is displayed in red.
Zero Set
Perform a zero-set whenever necessary, such as after you have turned on the power or when the
ambient temperature changes.
Performing zero set adjusts the internal deviation of the optical power measurement section and
enables you to obtain more accurate absolute optical power values. Perform zero set on the optical
power meter.
7.5 Using the Power Checker (/PC option)
