Instrumentation & Measurement Flashcards
7 cards from real ITMC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Instrumentation & Measurement flashcards as text
What is the primary function of a pressure transmitter in an industrial process?
Answer: To convert pressure readings into electrical signals for remote monitoring
A pressure transmitter converts measured pressure into a standardized electrical signal (typically 4-20 mA) that can be transmitted to a control system for remote monitoring and control.
What does RTD stand for in temperature measurement instrumentation?
Answer: Resistance Temperature Detector
RTD stands for Resistance Temperature Detector, a sensor that measures temperature by correlating the electrical resistance of a metal element with its temperature.
Why is the 4-20 mA signal standard preferred for transmitting process measurements over long cable runs?
Answer: Current signals are not affected by line resistance the way voltage signals are
Current signals maintain their value regardless of line resistance, so 4-20 mA is preferred for long-distance transmission where voltage drop across cable resistance would distort a voltage signal.
What is the primary operating principle of a thermocouple?
Answer: Two dissimilar metals joined at a junction generate a voltage proportional to temperature
A thermocouple operates on the Seebeck effect, where two dissimilar metals joined at a junction generate an electromotive force (voltage) proportional to the junction temperature.
Which type of sensor detects metallic objects without physical contact by generating an electromagnetic field?
Answer: Inductive proximity sensor
Inductive proximity sensors generate an oscillating electromagnetic field and detect metallic objects when they disturb the field, allowing non-contact detection.
What is zero suppression in pressure instrumentation calibration?
Answer: Calibrating so that a pressure above zero corresponds to the instrument's minimum output
Zero suppression calibrates an instrument so that a positive elevated pressure corresponds to the instrument's zero (4 mA) output, allowing measurement of a range that starts above absolute zero.
Which flow measurement device works by creating a restriction in the pipe and measuring the resulting differential pressure?
Answer: Orifice plate with differential pressure transmitter
An orifice plate creates a pressure drop proportional to flow velocity per Bernoulli's principle, and a differential pressure transmitter measures this drop to calculate flow rate.