How to maintain YOKOGAWA AQ7420 High Resolution Reflectometer?

RL/burn detection: AQ7420 test port → relay cable → FC/APC adapter → main cable → device under test (DUT), the open end of the main cable should be kept away from reflective objects (at least 100mm).

IL measurement: AQ7420 test port → relay cable → FC/APC adapter → main cable → DUT → AQ740023 sensor head, ensure that the connector end face is clean (dirt can cause excessive splicing loss, prompt "Under Range").

2. Measurement setup (Setup window)

Open the settings window through the "Setup" button on the main interface, configure measurement conditions, grading standards, data saving, and remote control parameters. The core settings are as follows:

(1) General settings

Operation mode: Supports three combination modes - "IL, RL, Detection" (single measurement of three types of parameters), "Detection" (only RL and burn detection), and "IL" (only IL).

Wavelength selection: main wavelength of 1.31 μ m, sub wavelength of 1.55 μ m (dual wavelength data can be measured simultaneously when sub wavelength needs to be enabled).

Start Position: Used for long-distance cable adjustment (optional accessory), input the distance compensation value displayed in the "Loopback Image" window to correct the measurement starting point offset.

(2) Measurement conditions

Scope of Settings/Option Description

Measurement distance (Span) from 0 to 100mm. The measurement time increases with distance and defaults to 100mm

RL measurement range -14.7~-85dB/-50~-100dB. The former is suitable for strong reflection scenarios, while the latter is suitable for weak reflection (such as deep loss)

The higher the sampling resolution of High (1 μ m)/Middle (4 μ m)/Low (8 μ m), the higher the measurement accuracy but the longer the time consumption

The average number of detections (Detection) is 1-16 times, and the more detections, the lower the noise

The refractive index (Index) of 1.0000~2.0000 is set according to the refractive index of the measured fiber (such as SM fiber 1.4674), which affects the accuracy of distance measurement

After turning on/off the Stability Mode, it automatically corrects the length drift of the main cable caused by changes in ambient temperature (0mm correction)

(3) Grading criteria (Analysis)

Set the qualified threshold for each parameter, and automatically compare and grade after measurement (blue "Pass", red "Fail"):

IL threshold: 0~40dB, supports setting display resolution (1/10~1/10000).

RL threshold: -120~-10dB, can limit the grading range (-10~110mm).

Burn detection threshold: -120~-10dB. Reflection peaks exceeding the threshold will be marked and counted on the waveform.

(4) Data saving settings

Storage path: Specify the data storage directory, enable "Auto Directory" to automatically create subfolders by "year/month/day".

File type: Waveform data supports CSV (numerical), JPG/BMP (image), measurement data (PS format) includes grading results, peak positions, and RL values, and dual wavelength data is merged and saved.

Auto Save: After enabling "File Save", save numerical data on a daily basis; The 'Waveform Save' supports modes such as' NG only auto save 'and' fully auto save 'to meet different testing needs.

3. Measurement operation process

(1) Reference measurement (taking PC polished DUT as an example)

RL/Burn Detection Reference (Detection REF):

Set the "Target Connector Selection" on the main interface to "PC", click on "Detection REF", and follow the prompts to connect the distance adjustment cable, relay cable, FC adapter, and PC polishing main cable (open end).

Click "OK" to perform the reference measurement. After completion, the command window will automatically close and record the reference reflection value at the 0mm starting point.

IL Reference (IL REF):

Click on "IL REF" on the main interface and connect the open end of the main cable to the optical input port of the AQ740023 sensor head.

Click "OK" to perform reference measurement, record the reference optical power, and use it for subsequent IL calculation (power difference after DUT insertion).

(2) DUT measurement

RL/Burn Detection Measurement:

Disconnect the main cable from the open end, connect the DUT (ensure the connector is clean and scratch free), and enter the DUT serial number (optional, supports automatic increment).

Click the "MEASURE" button on the main interface, and the instrument will scan the distribution of return loss within the measurement range. After completion, the RL value will be output in the "Measurement Result Display Area", and the waveform will display the burn detection peak.

IL measurement:

Connect the DUT in series between the main cable and AQ740023, click "Measure", and the instrument calculates the insertion loss of the DUT (the difference between the reference power and the measured power), and the result is displayed in real time (enabling "IL Realtime Mode" for continuous measurement).

4. Data analysis (Analysis window)

After the measurement is completed, click the "Analysis Mode" button on the main interface to enter the analysis window, which supports waveform detail viewing and marking analysis: