Source of question bank: Safety production mock exam, WeChat public account mini program
The 2021 new version of chemical automation control instrument test questions and chemical automation control instrument theory test, including the answers and analysis of the new version of chemical automation control instrument test questions and the practice of chemical automation control instrument theory test. Combining the latest syllabus of the national chemical automation control instrument exam and the summary of the real questions of the chemical automation control instrument exam from the safety production simulation exam Yidiantong public number, it is helpful to practice before the online chemical automation control instrument exam.
1. [True and True] The thermoelectric potential is the electromotive force generated by the different temperatures at both ends of the same metal and the different kinetic energy of free electrons. (√)
2. [Judgment] The purpose of the cascade control system is to stabilize the main variable with high precision. The main variable is required to be high, and the residual is generally not allowed, so the main controller generally chooses the PI control law; when the object lag is large , Can also introduce appropriate D effects. (√)
3. [True and True] The error of the instrument used in the production device or control system is only an additional error. (×)
4. [True and True] In the block diagram of the automatic control system, the comparison mechanism can be regarded as one of the "links". (×)
5. [True and True] The air opening and air closing of the regulating valve are consistent with its positive and negative effects. (×)
6. [Judgement Question] The international system of units for the flow coefficient of the regulating valve is expressed in KV (√)
7. [True and True] Reciprocating pumps, gear pumps, screw pumps, and centrifugal pumps are all positive displacement pumps. (×)
8. [True/True] After the operation station used for man-machine dialogue in the computer control system (such as DCS, ESD) fails, if it is restarted, the operation of the control station program will be interrupted. (×)
9. [True/True Question] The electronic electric actuator is characterized by high reliability, and the actuator can be free of maintenance within 5 to 10 years. (√)
10. [True and True] In actual circuits, any current whose direction does not change with time is called direct current. (√)
11. [True and True] The electroscope can only detect AC power. (×)
12. [True and True] In the PLC ladder diagram, the output relays of the same number can be repeatedly quoted as contacts. (√)
13. [True and True] The faster the flow rate of the fluid in the pipe, the smaller the pressure of the fluid on the pipe wall. (√)
14. [Judgment] The amplification factor of the interference channel should be as large as possible, the time constant should be as small as possible, the interference action point should be as close to the regulating valve as possible, and the capacity lag of the target interference channel should be increased to reduce the influence of interference on the controlled variable. . (×)
15. [True and True] When the liquid moves from the center of the rotating impeller to the outer edge, a low pressure (vacuum) zone is formed in the center of the impeller. (√)
16. [Judgement] For the PLC switch output unit of the relay output mode, the power supply of the load circuit can be either AC or DC. (√)
17. [Judgement Questions] Thermal mass flow meters can only be used in gases. The heat transfer and heat absorption capacity of various gases are used to measure the heat transfer or heat energy loss from heating to induction to correspond to the flow rate. (√)
18. [True and True] Fieldbus is an all-digital, two-way, multi-point communication line used to connect field intelligent equipment and automation systems. (√)
19. [Judgement Question] For objects with large lag, the proportional-differential control law can be used to overcome the object's inertia, and the control result has no margin. (×)
20. [True and True] Mass flow meter is a flow meter based on measuring fluid quality. (√)
21. [True and True] In the CENTUMCS3000 system, the function of the ESB bus in KFCS is to connect the FCU with the local node and between the local nodes. (√)
22. [True and True] The scan period of the DCS control station should be set as short as possible during configuration. (×)
23. [True and True] In the case of large fluctuations in the measured pressure, the normal operating pressure value should not exceed 2/3 of the full range of the pressure gauge; the highest should not exceed 3/4 of the full range. (×)
24. [True and True] The pipes of room temperature equipment in chemical plants also need to be insulated. (×)
25. [True and True] The emergency shutdown system (ESD), safety interlocking system (SIS), instrument protection system (IPS), and fail-safe control system (FSC) that we often talk about can all be called safety instrumented systems (SIS). (√)
26. [True and True] International Electrotechnical Commission (IEC) stipulates that only Exia-level intrinsically safe explosion-proof technology can be used in Zone 0, the most dangerous hazardous location. (√)
27. [True and True] Pneumatic retaining valve can automatically cut off the channel between the positioner output and the gas chamber of the regulating valve when the gas source pressure of the instrument is interrupted or the gas supply system fails to ensure that the process parameters in the regulating loop remain unchanged , After the fault is eliminated, the retaining valve will return to normal immediately. (√)
28. [Judgement] The shielding layer of the cable should be shielded and grounded, and the shielding ground can share the grounding trunk and grounding pole with the working ground. (√)
29. [True and True] heating methods are divided into jacket heating, strong heating, heavy heating and light heating. (√)
30. [True/Judgement] The flow coefficient of the regulating valve is expressed in KV in English units. (×)
31. [True and True] In stable heat conduction, the heat conduction per unit time is proportional to the heat conduction area. (√)
32. [True and True] Air filter pressure reducer is the most typical accessory, it is used to purify the air source from the air compressor, and can adjust the pressure to the required pressure value, and has the function of automatic voltage stabilization. (√)
33. [Single choice] Two-position four-way solenoid valve is widely used for () control. (B)
A, continuous
B. Sequence
C, remote control
34. [Single-choice questions] The cage valve has a large adjustable ratio, small vibration, small unbalanced force, and () interchangeability, which can obtain different flow characteristics. (A)
A. Sleeve
B. Spool
C, valve trim
35. [Single-choice questions] The spool is the key component of the control valve, in various forms, but it is generally divided into two categories, namely the straight-stroke spool and (). (B)
A, spherical valve core
B. Angle stroke spool
C. Flat penalty spool
36. [Single-choice questions] There are two types of vortex flowmeters: one of them is a flowmeter made by applying the principle of vortex column () called vortex flowmeter. (A)
A. Natural oscillation
B. Simple resonance
C. Forced oscillation
37. [Single-choice question] Through the calculation of the relevant parameters of the rotor flowmeter, it can be seen that when the density of the measured medium increases (greater than the density of water), and the other conditions (rotor shape, density, etc.) remain unchanged, the meter is converted Back range (). (A)
A, reduce
B. Increase
C, unchanged
38. [Single-choice question] The 3300 series eddy current sensor system measures the vibration and relative position by means of the gap between the probe tip and the surface of the conductor being observed, and converts it into a signal and sends it to the monitor. (B)
A. Proportional positive voltage
B. Positive proportional negative voltage
C. Inversely proportional positive voltage
39. [Single choice] The incorrect statement about the advantages of the eccentric rotary valve is (). (B)
A. Simple flow path, low resistance
B. Large unbalanced force
C. Large circulation capacity
40. [Single choice] Glass plate level gauge is a type of () gauge. (C)
A. Buoyancy
B. Differential pressure
C, direct reading
41. [Single-choice question] In the loop adjustment screen of the CENTUMCS3000 system, HH is (). (B)
A, given value
B. High and high alarm setting value
C. Output value
42. [Single-choice question] () theoretically refers to the difference between the indicated value of the instrument and the true value of the measured value. (B)
A. Relative error
B. Absolute error
C, accuracy
43. [Single-choice question] Among the straight stroke spools, the one with quick opening characteristics is the () spool. (A)
A, flat type
B. Plunger type
C, window type
44. [Single-choice question] The function of the electric pressure gauge is to convert the measured pressure into various electrical signals and perform () and display the pressure value. (B)
A, zoom in
B. Transmission
C. Conversion
45. [Single-choice question] Is the correct description of the cold junction temperature compensation taken by the thermocouple (). (B)
A. Lower the cold end to 0℃
B. Extend the cold end to the room with low temperature, and compensate the cold end temperature to 0℃
C. Cold junction compensation is to reduce the thermoelectric potential
46. [Single-choice questions] Pneumatic actuators have (). (A)
A. Positive and negative effects
B. Air on and air off
C, film type and piston type
47. [Single-choice question] Among the following valves, the one that is automatically opened and closed by the change of some parameters in the system is (). (B)
A, plug valve
B. Pressure reducing valve
C. Gate valve
48. [Single-choice question] There are two ways to choose the controlled variable in the control system, among which the process index (such as pressure, flow, liquid level, temperature, composition, etc.) is the controlled variable (). (C)
A. Indirect parameter index control
B. Control of related parameters
C. Direct parameter index control
49. [Single-choice question] Siemens S7-300 programmable control can accept field signals and convert them into different signals of the S7-300 template is (). (B)
A. Power supply template
B. Signal template
C. Interface template
50. [Single choice] Three-way valves are often used in (). (B)
A. High temperature occasions
B. Heat exchanger bypass adjustment
C. Where the leakage level is high
The above is the new version of the 2021 chemical automation control instrument test questions and the chemical automation control instrument theory test. Support the examination questions of precision chemical automation control instrument operation in all regions of the country, and support the exercises of the safety qualification certificate, special operation operation certificate, vocational skill appraisal and other types of work.