CTC Test Instrumentation and Measurement Systems Flashcards

A thermocouple in a CTC high-temperature test reads erratically. Which failure cause should the conductor investigate first?

Answer: A broken or corroded junction causing intermittent electrical contact

Erratic thermocouple readings most commonly result from a damaged or corroded junction creating intermittent contact, which is the first physical cause to verify.

What is the role of an anti-aliasing filter in a CTC data acquisition system?

Answer: It removes frequency components above half the sampling rate before digitization to prevent aliasing

Anti-aliasing filters attenuate high-frequency content above the Nyquist frequency before the analog-to-digital converter to prevent aliasing artifacts in recorded data.

Before a test, the CTC performs a multi-point calibration on a pressure transducer. Why is a multi-point calibration preferred over a single-point check?

Answer: It characterizes sensor linearity and identifies non-linear behavior across the measurement range

A multi-point calibration maps sensor output across the full range, revealing non-linearities that a single-point zero/span check would miss.

During a CTC test, a data channel suddenly flat-lines at zero volts. What should the conductor suspect first?

Answer: An open circuit in the sensor wiring or a failed sensor

A flat zero-volt output typically indicates an open circuit in the wiring or a completely failed sensor, which is the first hardware fault to investigate.

What does the term 'dynamic range' of a measurement system refer to?

Answer: The ratio between the largest and smallest signals the system can accurately measure

Dynamic range is the ratio between the maximum and minimum measurable signal levels within which the system maintains acceptable accuracy.

A CTC verifies that all data acquisition channels are synchronized to a common time source. Why is time synchronization critical?

Answer: It ensures that multi-channel data can be correctly correlated and events accurately time-stamped

Common time synchronization allows cross-channel correlation of events, which is essential for accurately reconstructing the sequence of test occurrences.