Testing Checklists
This domain covers the discipline that makes test data usable: what to check before, during and after a test campaign, and what must appear on a report for it to be accepted. Exam questions here are about process details that decide whether results can be compared with a standard.
Before testing
- Test plan: standard and edition, limits, wavelengths, reference method, direction, sampling, and who witnesses.
- Instruments: model, serial number, calibration date; the right adapters (2.5 mm, 1.25 mm, UPC, APC); launch and receive cables; known-good reference jumpers.
- Consumables: inspection scope, one-click cleaner, lint-free wipes, 99% isopropyl.
- Documentation: cable and fiber IDs, splice records, as-built loss budget, labeling scheme such as TIA-606.
- Safety and access: laser class awareness, live-fiber identification, site access, power for instruments.
During testing
- Inspect and clean every connection before mating, including the test jumpers.
- Set the reference at each wavelength, confirm 0.0 dB, and re-verify at the end of the day.
- Record raw readings as they happen, with wavelength and direction, not later from memory.
- Take bidirectional OTDR traces and keep the trace files with the fiber ID.
- Never mix reference methods within a campaign.
- Retest any outlier immediately, while you are still on site.
After testing
- Compare results to the computed loss budget, not only to a generic pass limit.
- Report fields: date, technician, standard, instrument model and serial, calibration date, wavelength, reference method, direction, measured value, pass or fail, trace file name.
- Deliver the report and archive the baseline data; a future fault is far easier to find with a known-good reference trace.
Worked example
A technician tests 24 fibers, all pass, but the report lists neither the reference method nor instrument calibration dates, and no trace files were saved. The customer rejects it. Reasoning: without the method, the numbers cannot be compared with any other campaign; without calibration dates, the readings have unknown uncertainty; without baselines, future fault location starts from zero. The re-test costs a second site visit.
Traps that cost marks
Recording only pass/fail and not the raw value; forgetting direction on OTDR data; storing traces only on the instrument; omitting the launch cable from the equipment list and losing the end connectors; testing after the customer has started patching.
Key points
- Confirm standard, limits, wavelength and reference method before the first measurement.
- Record instrument serial numbers and calibration dates on every report.
- Save OTDR trace files tagged with fiber ID and direction.
- Re-verify the reference at the end of each testing day.
- Compare results to the design budget, not just to a pass limit.
- Retest outliers on site, never from memory later.