2. Try to list three transducers of displacement measurement and state measurement mechanism respectively.
二．Proving problems
3. Prove the sum-difference characteristics of wheatstone bridge.
2) Draw the measurement diagram which started from sensors to display and state every parts’ function.
3) Try to determine frequency components at least in vibrate signal. 4) Determine the minimal sample frequency.
characteristic）
9. A gearbox
1) State principle of transducer selection. Choose a kind of vibration transducer to monitoring the gearbox and explain the reason.
6. A first order instrument with a a time constant of 0.35s is used to measure periodic inputs with inputs with the period 1,2,5s. Determine the amplitude error.
������������
=
������1������2 (������1 + ������2)2
(∆���������1���1
−
∆������2 ������2
+
∆������3 ������3
−
∆���������4���4)������������
三．Calculation questions 4. A frequency response fuction of a system is shown following 3155072 T(������ω) = (1 + 0.01������ω)(15577536 + 176������ω − ω2) If the input signal x(t) = 5sin⁡(10t),try to calculate the mean and RMS values of its
7. A amplitude modulation waveform x������(t) = (50 + 20cos2����1������ + 1020cos6����1������)cos2����������������
1) Calculate frequencies and amplitudes of each component frequency for amplitude modulation waveform.
steady state response.
5. In order to measure the torque characteristics of a rotating shaft. 1) Determine the direction of principal stress(主应力) 2) State the deploy method of strain gauges and try to draw the deploy position of the strain gauges and measurement circuit. 3) Try to analyze the method of compensation in strain measurement
2) Draw the spectrum plot of the modulation signal and amplitude modulation signal.
8. The amplitude spectrum of signal is shown
A(ω)
6
5
3
φ（ω）
������ 2
3
9
ω

3
9
1) Write the mathematical expression of the signal 2) State characteristic of this kind of signal 3) Calculate the spectrum using Fourier Transform 4) Analyze the difference between the examination question and 3 ）（ spectrum’s
东南大学测试技术 2018 期末试卷
一．Brife questions 1. state the condition of Non-distorted measurement.How to adjust the paraments of a first order system to make the Non-distorted pass band width wider.