第一章 单元测试

1、多选题：
What are the characteristics of the measurement?（ ）。
选项：
A:Relative
B:Descriptive
C:Selective
D:Objective
答案: 【Descriptive;
Selective;
Objective】

2、单选题：
In a mercury thermometer as seen in this figure, which one is the sensing element?（ ）。
选项：
A:Scale
B:Bulb
C:Stem
D:Mercury in the bulb
答案: 【Mercury in the bulb】

3、多选题：
What components are there in a complex measurement system ?（ ）。
选项：
A:Data processing
B:Output
C:Signal conditioning
D:Sensor
答案: 【Data processing;
Output;
Signal conditioning;
Sensor】

4、判断题：
Selectivity is a necessary but not sufficient aspect of measurement. （ ）
选项：
A:对
B:错
答案: 【对】

5、判断题：
There are two different systems for the units of length, the metric units and the customary units?（ ）
选项：
A:对
B:错
答案: 【对】

6、判断题：
Any physical quantity can be expressed in terms of the base units. （ ）
选项：
A:对
B:错
答案: 【错】

7、判断题：
The additional units are independent to each other, but not independent to the base units. （ ）
选项：
A:对
B:错
答案: 【错】

8、多选题：
In SI units, there are different kinds. They are ?（ ）。
选项：
A:Additional units
B:Base units
C:Secondly units
D:Derived units
答案: 【Additional units;
Base units;
Derived units】

9、多选题：
In the follow units, who are base units ?（ ）。
选项：
A:Radian
B:Kilogram
C:Meter
D:Second
答案: 【Kilogram;
Meter;
Second】

10、单选题：
In the follow units, which one is not the derived units ?（ ）。
选项：
A:Hour
B:Hertz
C:Ampere
D:Watt
答案: 【Ampere】

11、多选题：
In SI system, there are different levers of standards, they are（ ）。
选项：
A:Working standards
B:Reference standards
C:Primary standards
D:Secondary standards
答案: 【Working standards;
Primary standards;
Secondary standards】

12、判断题：
The International Prototype Meter is the primary standard of length. （ ）
选项：
A:错
B:对
答案: 【对】

13、判断题：
All measurements of continuums involve errors. （ ）
选项：
A:错
B:对
答案: 【对】

14、单选题：
In a measurement we get the measured value is 50mm. if the true value is 50.02mm, then what is the measurement error?（ ）。
选项：
A:0.02mm
B:-0.02mm
C:50mm
D:50.02mm
答案: 【-0.02mm】

15、判断题：
A true value is the value that an object really exists when it is measured, and it can be obtained by measurement. （ ）
选项：
A:错
B:对
答案: 【错】

16、多选题：
What are the characteristics of the random errors?（ ）。
选项：
A:are unpredictable.
B:may be predicted and hence eventually removed from data
C:the values are very small
D:cannot be corrected
答案: 【are unpredictable.;
the values are very small;
cannot be corrected】

17、单选题：
In a length measurement, we measure the length 10 times and get the average length 1.55m, and the uncertainty of the measurement is 5cm. Then the measured length is（ ）。
选项：
A:1.50m
B:(1.55±5)m
C:(1.55±0.05)m
D:1.60m
答案: 【(1.55±0.05)m】

18、单选题：
Which one is not the static characteristic of a transducer ? （ ）
选项：
A:Damping
B:Accuracy
C:Hysteresis
D:Sensitivity
答案: 【Damping】

19、单选题：
In a measurement, the full scale of the transducer is 100 millivolts, and the difference between the increasing run and the decreasing run is 25 millivolts, Then what is the hysteresis of the transducer? （ ）
选项：
A:25 millivolts
B:25%
C:100 millivolts
D:0.25 millivolts
答案: 【25%】

20、单选题：
To calibrate the deadband of a transducer by slowly increasing the input signal. If the noted input is 5μm, and the span of the transducer is 10mm. The deadband error is （ ）
选项：
A:5μm
B:0.05%
C:0.5%
D:5%
答案: 【0.05%】

21、单选题：
In the calibration of the linearity of a transducer, the maximum difference between the measured value and the calibration curve is -0.25 volts, and the full span of the transducer is 10 volts. The linearity error is （ ）
选项：
A:2.5%
B:-2.5%
C:-0.25 volts
D:0.25%
答案: 【-2.5%】

22、单选题：
To calibrate the sensitivity of a thermometer. When temperature is changed from 0ºC to 100ºC, the resistance changes from 100 ohm to 153.5 ohm. The sensitivity for this range is （ ）
选项：
A:53.5 ohm
B:0.535 ohm/ºC
C:0.535
D:53.55%
答案: 【0.535 ohm/ºC】

23、判断题：
Dynamic characteristics, describes the characteristics that are determined while the system is measuring a time-varying signal. （ ）
选项：
A:对
B:错
答案: 【对】

24、判断题：
The measurement system can be used to measure frequencies close to the corner frequency. （ ）
选项：
A:对
B:错
答案: 【错】

25、单选题：
For a dynamic measurement system or sensor, if the damping ratio ζ is 0.77, it is （ ）
选项：
A:critically damped
B:over damped
C:Underdamped
D:others
答案: 【Underdamped】

第二章 单元测试

1、判断题：
Sensor is a device that senses a physical stimulus and converts it into a signal, usually electrical, mechanical or optical. （ ）
选项：
A:错
B:对
答案: 【对】

2、单选题：
In below picture, which expression is right? （ ）

选项：
A:High accuracy and high precision
B:High accuracy and low precision
C:Low accuracy and low precision
D:Low accuracy and high precision
答案: 【Low accuracy and high precision】

3、判断题：
Displacement is defined as the difference between the initial position of something and any later position. （ ）
选项：
A:错
B:对
答案: 【对】

4、多选题：
Possible measurement of a displacement transducer can be（ ）。
选项：
A:Thickness
B:velocity
C:Position
D:Width
答案: 【Thickness;
Position;
Width】

5、单选题：
Which one is not the type of capacitive sensor（ ）。
选项：
A:Area variation
B:Spacing variation
C:Medium variation
D:Angle variation
答案: 【Angle variation】

6、判断题：
Generally the spacing variation capacitive sensor is suitable to small displacement measurement because of the parabolic capacitance-motion relationship. （ ）
选项：
A:对
B:错
答案: 【对】

7、判断题：
For all kinds of the area variation capacitive sensor, the relationship between the input displacement and the output capacitance is linear. （ ）
选项：
A:对
B:错
答案: 【对】

8、单选题：
The sensitivity k of a medium-variation capacitive sensor is（ ）。
选项：
A:
B:
C:
D:
答案: 【】

9、单选题：
To measure the thickness of a steel sheet, which type of capacitive sensor can we use?（ ）。
选项：
A:Spacing variation
B:Area variation
C:Angle variation
D:Medium variation
答案: 【Medium variation】

10、判断题：
In a mutual inductance sensor, there must be at least two coils. （ ）
选项：
A:错
B:对
答案: 【对】

11、多选题：
In sensors, differential structure is often used be（ ）。
选项：
A:Lower interference
B:Better linearity
C:Faster dynamic response
D:Double sensitivity
答案: 【Lower interference;
Better linearity;
Double sensitivity】

12、单选题：
What kind of inductive sensor is it shown in below picture?（ ）。
选项：
A:Area variation self-inductance sensor
B:Angle-variation inductance sensor
C:Gap-variation self-inductance sensor
D:Mutual inductance sensor
答案: 【Area variation self-inductance sensor】

13、判断题：
Linear Variable Differential Transformer (LVDT) is a mutual-inductive sensor. （ ）
选项：
A:对
B:错
答案: 【对】

14、多选题：
What are the advantages of LVDT?（ ）。
选项：
A:High sensitivity
B:Big temperature range
C:High linearity
D:High signal to noise ratio
答案: 【High sensitivity;
Big temperature range;
High signal to noise ratio】

15、多选题：
About Eddy-current effect, what are right below?（ ）。
选项：
A:It is also called Skin effect.
B:It is the operation principle of Eddy Current sensors.
C:The Eddy Current is in the sensing coil.
D:The Eddy Current will create an opposing magnetic field which resists the original magnetic field.
答案: 【It is also called Skin effect.;
It is the operation principle of Eddy Current sensors.;
The Eddy Current will create an opposing magnetic field which resists the original magnetic field.】

16、判断题：
To measure the thickness of a steel sheet, we should use reflective mode with low frequency of Eddy Current sensor. （ ）
选项：
A:对
B:错
答案: 【错】

17、多选题：
What can Eddy current displacement sensors be used for? （ ）
选项：
A:Thickness measurement of a steel sheet
B:Rotating speed indicators
C:Non-destructive testing
D:Braking machanism in trains
答案: 【Thickness measurement of a steel sheet;
Rotating speed indicators;
Non-destructive testing;
Braking machanism in trains】