Diagnostic and Testing Tools Flashcards
7 cards from real AET practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Diagnostic and Testing Tools flashcards as text
When using a clamp-on ammeter to measure AC current in an aircraft wiring harness, the technician should ensure which of the following?
Answer: Only one conductor passes through the clamp jaw
A clamp-on ammeter measures the magnetic field produced by a single conductor; placing multiple conductors cancels their fields and gives a false reading.
A Time Domain Reflectometer (TDR) is primarily used in aircraft maintenance to:
Answer: Locate faults and determine their distance in coaxial or wire runs
A TDR sends a pulse down a conductor and analyzes the reflected signal to pinpoint fault location and distance.
Which instrument is the correct tool for verifying the output frequency of an aircraft inverter?
Answer: Frequency counter or oscilloscope
A frequency counter or oscilloscope directly measures the cycles per second of an inverter's AC output.
A logic probe displaying a steady LOW on a digital avionics bus line most likely indicates:
Answer: The line is being held at ground potential or is open
A steady LOW typically means the line is being actively pulled to ground or is open with a pull-down resistor.
What is the primary purpose of a breakout box in avionics troubleshooting?
Answer: To provide access points to individual pins of a connector without removing it from the LRU
A breakout box intercepts the connector to expose each pin for measurement while the unit remains in its normal circuit configuration.
When performing a capacitor leakage test with an LCR meter on an aircraft power supply filter capacitor, an excessively high leakage current reading indicates:
Answer: The capacitor's dielectric is degraded or the unit is shorted internally
High leakage current through a capacitor signals dielectric breakdown or an internal short, requiring replacement.
A spectrum analyzer is preferred over a standard oscilloscope when troubleshooting an aircraft VHF communications system because it:
Answer: Shows signal energy distribution across frequencies, revealing spurious emissions
A spectrum analyzer presents amplitude versus frequency, making it easy to identify harmonic spurs or interference that an oscilloscope cannot easily separate.