QUESTIONS AND ANSWERS 2025
Static Measurement - ANSWER-when the quantity measured does not change in
value (it is steady)
-only the signal magnitude is needed to reconstruct the input signal based on the
indicated output signal (such as the value indicated by a ruler)
-the output is IMMEDIATELY displayed
Dynamic Measurement - ANSWER-quantity measured varies with time
-signal amplitude, frequency, and general waveform information are needed to
reconstruct the input signal
-the measurement system must be fast enough to keep up with input signal
-Ex. reading from a thermometer is dynamic event since it takes time to reach the
"true" value as the system reaches thermal equilibrium
General Model of Measurement System - ANSWER-the system senses an input
signal and translates this information into a quantifiable output form
-a general measurement system can be represented by a differential equation
-the output y(t) of an instrument/system is based on input F(t), the forcing function
Different Types of Measurement Systems - ANSWER0th Order
-immediate response, no storage
-no inertia in sensor or system
1st Order
-simple delayed response
-measurement system absorbs
-stores energy when sensing variable
2nd Order
-Delayed response w/ potential oscillation
-measurement system dissipates
-stores energy
-requires moving and inertial component
Zero Order Systems - ANSWER-perfect performance with instant response
-ODE: a0y = F(t) [NO DERIVATIVE COMPONENTS]
-Solution: y(t) = KF(t) where K = 1/a0
-only depends on one physical parameter K which is the static sensitivity (dy/dx)
-if input is F(t) = A, the output is KA