DCI Tools & Equipment Operation 5 — Questions and Answers
Question 1: A technician uses a fusion splicer and the splice loss reads 0.35 dB, which exceeds the acceptable limit of 0.1 dB. What is the most likely cause?
- The splicer's arc current is too low
- Contaminated or improperly cleaved fiber end faces (Correct answer)
- The fiber is too long for fusion splicing
- The splicer is the wrong model for single-mode fiber
Correct answer: Contaminated or improperly cleaved fiber end faces
High splice loss almost always results from dirty, chipped, or non-perpendicular end faces; cleaning and re-cleaving typically resolves elevated splice loss readings.
Question 2: What is the correct procedure for using a conduit bender to make a 90-degree bend without kinking EMT conduit?
- Make three successive 30-degree bends at the same mark
- Place the bender's arrow at the measured take-up point, apply steady foot pressure while watching the degree indicator, and stop at 90 degrees (Correct answer)
- Bend past 90 degrees and spring back to 90 degrees
- Heat the conduit first, then bend by hand
Correct answer: Place the bender's arrow at the measured take-up point, apply steady foot pressure while watching the degree indicator, and stop at 90 degrees
Proper conduit bending requires accounting for the bender's take-up (stub length offset), applying steady pressure, and stopping at exactly 90 degrees using the bender's angle indicator.
Question 3: A technician notices the fish tape is binding inside a conduit. Which of the following actions is most appropriate?
- Apply more pulling force to push through the obstruction
- Withdraw the tape, inspect for kinks or obstructions, lubricate the tape, and re-feed carefully (Correct answer)
- Cut the fish tape at the bend and retrieve it from the other end
- Switch to a larger diameter fish tape
Correct answer: Withdraw the tape, inspect for kinks or obstructions, lubricate the tape, and re-feed carefully
Withdrawing and lubricating the fish tape, then inspecting the conduit path for bends or debris, is the safe approach — forcing a binding tape can damage conduit fittings or break the tape.
Question 4: Which measurement parameter does a Time Domain Reflectometer (TDR) use to calculate cable length?
- Signal amplitude at the far end
- The round-trip travel time of a reflected pulse combined with the cable's Nominal Velocity of Propagation (NVP) (Correct answer)
- Cable resistance per foot
- Insertion loss at 100 MHz
Correct answer: The round-trip travel time of a reflected pulse combined with the cable's Nominal Velocity of Propagation (NVP)
A TDR sends a pulse and times the reflection; multiplying half the round-trip time by the NVP (expressed as a fraction of the speed of light) gives the cable length.
Question 5: When pulling multiple CAT 6A cables simultaneously through conduit, what is the maximum recommended percentage of conduit fill for three cables?
- 53% fill
- 40% fill (Correct answer)
- 60% fill
- 75% fill
Correct answer: 40% fill
NEC and standard practice limit conduit fill to 40% of the conduit's interior cross-sectional area when pulling three or more conductors or cables.
Question 6: A label printer used for cable identification prints smeared text. What is the most likely cause and solution?
- Label stock is too thin — use thicker labels
- The print head is dirty or the label cartridge is incompatible — clean the head and verify the correct cartridge type (Correct answer)
- The printer battery is low — replace the battery first
- The cable diameter exceeds the printer's label width — use wider labels
Correct answer: The print head is dirty or the label cartridge is incompatible — clean the head and verify the correct cartridge type
Smeared printing in thermal transfer label printers is usually caused by a dirty print head or using labels incompatible with the printer's print method; cleaning and matching cartridge type resolves the issue.
Question 7: Which instrument is required to verify that a grounding and bonding conductor for a telecommunications room is properly connected and meets resistance requirements?
- Inductive amplifier
- Low-resistance ohmmeter or earth ground tester (Correct answer)
- Digital voltage meter set to AC
- Cable certification tester
Correct answer: Low-resistance ohmmeter or earth ground tester
A low-resistance ohmmeter (micro-ohmmeter) or earth ground tester measures the continuity and resistance of bonding conductors and ground electrode systems to verify they meet TIA-607 requirements.
DCI Tools & Equipment Operation 5
A technician uses a fusion splicer and the splice loss reads 0.35 dB, which exceeds the acceptable limit of 0.1 dB.
What is the most likely cause?