Request: Question bank for instrument repair technicians – advanced level

Senior Instrument Repair Technician http://bbs.hcbbs.com/thread-147333-1-9.html

Thank you to the student on the second floor; it’s just that many questions are missing here

Advanced Technician Exam Questions I. Fill in the blanks 1. When calibrating instruments, the basic principles that should be followed regarding data recording and data processing are (　　　). 2. Errors resulting from measurement methods and theories belong to ( ) errors. 3. The accuracy of a gauge is related not only to ( ), but also to the ( ) of the gauge. 4. The relative percentage error, nonlinear error, and variability that indicate the accuracy of a meter refer to the errors that occur after the meter has completed its detection process; these are all considered （） errors. 5. During the overspeed test of a steam turbine, it is necessary to check the （） of the overspeed signal as well as the （　　　） of the protective devices. 6. There is distributed capacitance between the interference wires and the sleeve, as well as between the sleeve and the signal wires; therefore static induction is likely to occur. Only when （　　） will this static induction disappear. 7. Differential capacitive differential pressure transmitters mainly consist of ( ) and ( ). 8. Commonly used pressure calibration instruments are ( ) and ( ). 9. Classified by working principle, level measurement instruments can be divided into ( ), (　　), (　　), (　　), (　　), (　　) and other types. 10. To address the problems of corrosion and blockage in pressure transmission pipelines, （　　） can be used. The （　　） of this type of transmitter is connected directly to the flange on the container, and the sealed system composed of the diaphragm box, capillary tube, and measurement chamber is filled with （　　） as the pressure transmission medium. 11. The dual closed-loop ratio regulation system consists of （ ） closed loops; when the primary parameter changes due to disturbances, the secondary parameter （　　　）， and when the secondary parameter changes due to disturbances, the primary parameter （　　　）。 12. The flow control methods for centrifugal pumps include (　　　), (　　　), (　　　), etc. 13. Under normal circumstances, an （ ） actuator should be used; for large-diameter valves and those with high pressure differences, an （ ） actuator is appropriate; for butterfly valves that require high torque, an （ ） actuator is needed. 14. With the development of DCS and PLCs, the boundary between the two is becoming increasingly （ ）， and their functions are becoming more （ ） to each other. 15. The main characteristics of the third-generation distributed control system are ( ). 16. Since the 1970s, microcomputer-based distributed control systems have integrated the latest achievements of modern high technology, namely ( ), ( ), ( ) and ( ), enabling automated instrumentation devices to make a qualitative leap toward systematization, decentralization, diversification, and higher performance. 17. A Programmable Logic Controller (PLC) is a new type of universal automatic control device that integrates ( ), ( ) and ( ). 18. The output signals of modern programmable logic controllers include ( ), ( ), ( ) pulse signals as well as analog signals. 19. The connection between the differential pressure gauge or differential pressure transmitter ( ) and the measurement pipeline must be correct; the inclination direction and slope of the pressure lead pipes, as well as the installation of ( ), ( ), ( ), and ( ), must all comply with the specifications outlined in the design documents. 20. The integrated control system is a general term that includes ( ) systems, ( ) systems, ( ) systems, field control systems, and computer-integrated manufacturing systems, among others. 21. Instrument control systems include ( ), ( ), ( ), interlock systems, and integrated control systems, etc. 22. To make the flow coefficient α of the orifice flow meter stable, the Reynolds number of the fluid should be greater than ( ). 23. Temperature changes affect the magnitude of the Coriolis force (), but not the distortion of the measuring tube (), because temperature changes influence the elastic coefficient of the flow tube (). 24. Hydrostatic level gauges operate based on the principle of fluid ( ), and they can be divided into two main categories: ( ) type and ( ) type. 25. Various types of radiation have different energies; for the same type of radiation, the higher its ( ), the stronger its ( ) ability. 26. The rays used in industrial nuclear instruments are mostly ( ), ( ), ( ) rays, and ( ) rays are also used. 27. From the perspective of PLC application systems, the system can be divided into ( ) and ( ). II. True or False Questions 1. Increasing sensitivity can improve the accuracy of the instrument. ( ) 2. The accuracy of the instrument is numerically equal to the basic error. ( ) 3. In instrument installation, if there are specific requirements, try to minimize the length of the pipelines used for installation in order to reduce the delay in the dynamic characteristics of the instrument. ( ) 4. The basic principle that should be followed in data processing is objectivity. ( ) 5. pH electrodes of the 4973 series should be stored in a dry, room-temperature environment when not in use for extended periods. ( ) 7. When the pressure to be measured is not high, and the pressure gauge and the pressure sampling point are not at the same height, it is necessary to correct the measurement errors resulting from this height difference. ( ) 8. Ultrasonic level gauges cannot be used to measure the level of substances at high temperatures, as their probes cannot withstand such high temperatures. ( ) 9. When a programmable controller is set to operate in heat-start mode, if power is lost during operation, the instrument will switch to manual mode upon re-powering, with its output value remaining unchanged from the previous value. ( ) 10. When the stability and performance of a control system do not meet the specified requirements, it is possible to make adjustments by changing the structure and parameters of the system other than those related to the controlled system, or by adding certain components. ( ) 11. The selection of on-air and off-air valves is primarily based on practical considerations related to the process. When the signal pressure is interrupted due to faults or other issues, it is important that the valve remain in either the fully open or fully closed position in order to prevent damage to equipment and protect operators. ( ) 12. The development trend of DCS systems is toward production management systems that integrate control and management, namely Computer Integrated Manufacturing Systems (CIMS). ( ) 13. In digital circuits, high voltage and low voltage refer to certain voltage ranges, rather than fixed values. ( ) 14. The protective grounding system for instruments should be connected to the protective grounding network of low-voltage electrical equipment in electrical engineering; the connection must be firm and reliable, and series grounding is permissible. ( ) 15. Control instruments can have functions such as signal conversion, calculation, recording, display, operation, control, execution, monitoring, and protection. A controller is sometimes also called a regulator. ( ) 16. Instruments and equipment for measuring acids and bases can be installed in acid and base rooms; other instruments shall not be installed there. ( ) 17. The purpose of heat treatment is to improve the properties of metal materials. ( ) 18. The two end faces of a symmetric orifice plate have no cone angles, and the technical requirements for these two end faces are identical; therefore, the flow direction of the orifice plate is not fixed. ( ) 19. Target flowmeters are suitable for flow measurement at low Reynolds numbers; therefore, there is no such thing as a limit Reynolds number. ( ) 20. When a target flow meter is installed vertically on a pipeline, the fluid should flow from bottom to top. ( ) 21. If a analog transmitter is equipped with a microprocessor, it becomes an intelligent transmitter. ( ) 22. The larger the range ratio of a transmitter, the better its performance; therefore, when selecting an intelligent transmitter, it is essential to consider the size of its range ratio. ( ) 23. The zero point and range of the intelligent transmitter can be set and modified on the handheld communicator, so there is no need to use a pressure signal for calibration. ( ) 24. The sensor of the Rosemount 3051C intelligent transmitter is a silicon capacitive type; it converts the parameter being measured into a change in capacitance, and the measured differential pressure or pressure value is obtained by detecting this capacitance change. ( ) III. Multiple-choice questions 1. The pressure and temperature corrections made in flow compensation are used to correct ( ) errors. A. Systematic errors ； B. Random error ； C. Negligence error ； D. Additional error 2. If a 1151 pressure transmitter has a grounding issue in its wiring, then ( ). A. The voltage will decrease ； B. Voltage increase ； c. Current decreases ； D. The current increases. 3. When measuring a stable pressure, the maximum operating pressure of the medium being measured shall not exceed ( ) of the instrument’s range. A. 1/2 ； B. 1/3 ； C. 2/3 ； D. 3/5 4. A 1151 pressure transducer has a measurement range of 0–300 kPa. If the zero point shifts upward by 50%, then the instrument’s actual measurement range will be ( ). A. 150kPa ； B. 300kPa ； C 450kPa ； D. 250kPa 5. If it is found that the range of a pressure transmitter is too small when it is in use on-site, and the transmitter’s range is increased while the range of the secondary display instrument remains unchanged, then the measured pressure value will be ( ) compared to the actual pressure value. A. higher ； B. Too small ； C. Unchanged 6. Among the quality indicators of transition processes, the residual error represents ( ). A. The difference between the new stable value and the given value ； B. Difference between measured value and given value ； C. Adjust the difference between the parameter being adjusted and the reference parameter ； D. The difference between the overshoot and the set value. 7. Regarding the block diagram of a control system, which statement is correct? ( ) A. A square represents a device ； B. The lines connecting the squares represent the material relationships between them ； c. The lines connecting the squares represent the energy relationships between them ； D. The lines connecting the squares merely represent signal relationships. 8. In the regulation of boiler combustion, which type of air volume control is generally used? A. Uniform control system ； B. Ratio control system ； C. Feedforward control system ； D. Three-Impulse Regulation System 9. When studying dynamic characteristics, ( ) can be regarded as the input to the system’s element. A. Disturbances ； B. Control is effective ； C. Interference and control effects ； D. Measurement instrument signals 10. The correct choice for the type of valve used in the compressor anti-surge control is ( ). A. Valve-mounted before the compressor ； B. Air-operated type ； C. Air-shutoff type ； D. Post-valve type 11. For the single- and double-seat control valves produced in China, the R value is generally ( ). A. 10 ； B．30 ； C. 50 12. ( ) operates in a scanning manner. A. Programmable Logic Controller ； B. Industrial computer ； C. Ordinary PC ； D. Microcontroller 13. For Siemens PLCs, FB stands for ( ). A. Function block ； B. Tissue block ； C. Function call ； D. Data block 14. The only direction in which a hydraulic jack may be used during operation is ( ). A. Horizontal ； B. Vertical ； C. Inclination ； D. Any direction 15. To analyze the distribution of quality data, use ( ). A. Control chart ； B. Pareto chart ； C. Histogram ； D. Cause-and-effect diagram 16. Special processes refer to ( ). A. Processes that require special skills or techniques ； B. Processes with special quality requirements ； C. Processes whose processing quality cannot be determined through subsequent product verification and testing ； D. Key processes 17. The direction of fluid flow in a rotameter is ( ). A. From top to bottom ； B. Bottom-up ； C. All of them. 18. When using the pressure method to measure the liquid level in an open container, the height of the liquid level depends on ( ). A. Location of the pressure measurement point and container cross-section ； B. Location of the pressure measurement point and density of the medium; C. Density of the medium and cross-sectional area. 19. During actual operation, the valve position of a control valve should be at （ ） for optimal performance. A、30%～80% ； B, 15%～90% ； C、20%～100% 20. A pneumatic valve actuator shows no output pressure despite an input signal; what do you think are the main causes? ( ) A、Faults such as sticking of the valve internals ； B. Amplifier failure ； C. Nozzle baffle fouling 21. To control fluids with high viscosity, fibers, and fine particles, which option is the most suitable? A. Butterfly valve ； B、Sleeve valve ； C、Straight-through two-seat valve ； D. Eccentric rotary valve. 22. The sensor of the ST3000 series intelligent transmitter is ( ). A. Silicon capacitor ； B. Compound semiconductors ； C. Silicon resonance: 23. The response time of double-flange transmitters is longer than that of ordinary transmitters. In order to reduce the transmission time of flange transmitters, the ambient temperature of the transmitter ( ) A. should not be too low ； B. It should not be too high ； C. It must remain constant. 24. There is a flange with the specification ANSI 150 LB 3″; its actual operating pressure is ( ). A. 150LB ； B、Greater than 150LB ； C. It may be greater than or less than 150 LB. 25. When the gas to be analyzed contains solid or liquid impurities, the elevation angle between the axis of the sampling component and the horizontal line should be greater than ( ) degrees. A, 20 ； B, 15 ； C, 30 ； D、45 26. In the block diagram of a cascade control system, there are ( ). A、two controllers ； B. Two transmitters ； C. Two control valves ； D. Two objects under test ； E. Two given values: 27. Quality management is an important part of an organization’s ( ) activities. A. Functional management ； B. Professional management ； C. Comprehensive management ； D. Economic Management IV. Short Answer Questions 1. For different media, what is the effective insertion depth of the sleeves of thermocouples and thermal resistors into those media? 2. What precautions should be taken when using an electric grinder? 3. What conditions must be met before installing equipment in a comprehensive control system? 4. What requirements must be satisfied for cable laying? 5. Circuit testing should be carried out before the system is put into operation; what conditions are required before such testing? 6. What are absolute error, relative error, and reference error? 7. When using a throttling device in combination with a differential pressure transmitter to measure flow rate, what role does the condenser play? What are the requirements for the condenser? 8. Why are different methods used to calibrate differential pressure transmitters when measuring steam flow rate and liquid flow rate? 9. When a differential pressure transmitter is used to measure liquid flow, if the transmitter is installed at a higher position than the throttling device, describe the methods for venting air before starting up the instrument, as well as the precautions to take. 10. What are the two methods for zeroing an EJA-type intelligent transmitter? 11. What is meant by the weight-hanging method for calibrating float level gauges? 12. What is the phenomenon of false level readings in steam drums? 13. What is a static mathematical model? 14. What is a fieldbus? What are its characteristics? 15. When using an orifice plate to measure flow, why is it reasonable to install the orifice plate in front of the control valve? 16. How should the three-valve assembly of instruments be operated, and what precautions should be taken? 17. What components make up China’s explosion-proof marking system? Explain the meaning of each component. 18. What is an intrinsically safe associated device? Does it have explosion-proof capabilities? 19. What is isolation? Under what circumstances should isolation be used for measurements? 20. What is purging? In which situations is purging applicable? 21. How are the forward and reverse action directions defined for the controlled process, control valves, and controllers? 22. How can one check whether there is grease inside an oxygen pressure gauge? 23. There is an EJA smart transmitter whose output does not change after it is started up. How should this be checked? 24. How many methods are there for calibrating float level gauges? 25. What are the special requirements for calibrating electric contact pressure gauges? 26. What is a standard throttling device? What is a non-standard throttling device?

V. Calculation Problems
1. The pressure of the medium to be measured is 1.0 MPa. The ambient temperature around the instrument is ta = 55°C. A Bourdon tube pressure gauge is used for measurement, with a required measurement accuracy of δa = 1%. Determine the measurement range Pd and accuracy class δd of this pressure gauge. (The temperature coefficient β is 0.0001.)
2. A single-flange level gauge is used to measure the liquid level in an open container. The gauge has been calibrated, but due to maintenance needs, its installation position was lowered by a distance ΔH. Calculate how the gauge’s indication will change as a result, and determine what actions should be taken.
3. Explain through derivation how a float level gauge measures the liquid level, and what are the conditions under which it functions.
4. In industry, the hydraulic pressure at the bottom of storage tanks is often used to calculate the mass of liquid contained within the tank. As shown in the diagram, a pipe is first inserted into the tank, and compressed air is then fed into this pipe. When bubbles start to emerge from the liquid surface, the stop valve is closed to stop the air supply. The pressure at point B is measured to be 0.16 MPa. If the cross-sectional area of the tank is 500 m² and the distance from the bottom of the tank to the side walls is 8 m, what is the mass of the liquid in the tank?
5. A float level transmitter is used to measure the water level in a boiler’s drum. Under normal operating conditions, the pressure of saturated steam is 10.00 MPa (absolute pressure). The density of saturated water is ρW = 688.4 kg/m³, while the density of saturated steam is ρS = 55.6 kg/m³. The length of the float is L = 800 mm. This float transmitter was calibrated using water with a density of ρl = 1000 kg/m³, with the effect of saturated steam being ignored (i.e., ρS is considered to be 0). Calculate the water level indicated by the gauge when the actual water level in the drum drops to 0% under normal operating conditions.
6. Simplify the block diagram shown in the figure and write down the closed-loop transfer function. 7. Simplify the block diagram of the transfer function shown in the figure and write down the transfer function. 8. Determine the transfer function for the logarithmic amplitude frequency response shown in the figure, and calculate the dynamic parameters. 9. In a certain ratio control system, the range of the primary flow meter transmitter is F1 = 0–1600 m3/h, while the range of the secondary flow meter transmitter is F2 = 0–2000 m3/h ； A differential pressure signal is generated by the orifice plate, with a square-root function; the process requirement is that F2/F1 = 3. Determine what coefficient the ratio controller should have. 10. In a ratio control system composed of pneumatic unit instruments, the range of the pneumatic ratio controller is 0–4, while the signal range is 0.2–1.0 bar (1 bar = 10^5 Pa). During operation, it was measured that the output signal of the ratio controller was 0.6 bar. What is the ratio coefficient at this time? 11. In a ratio control system using electric type III instruments, the range of the primary flow rate is 0–400 Nm³/h, and that of the secondary flow rate is 0–600 Nm³/h. During operation, the instrument operator measured that the output current of the ratio controller was 12 mA. Assuming the use of a square root function, what is the ratio of the primary to secondary flow rates? (The range of the ratio controller is 0–4.) 12. There are two pneumatic diaphragm sleeve control valves, each with an adjustable ratio of R1 = R2 = 50. The maximum flow rate for the first valve is Q1max = 100 m³/h, while that for the second valve is Q2max = 10 m³/h. What is the adjustable ratio when using split-range control? 13. What is the weight of a steel pipe with a diameter of Φ273×10 per meter? (Given that the density of steel is ρ = 7800 kg/m³)

VI. Essay Questions
1. What is the purpose of uniform control?
2. Describe the methods for tuning the parameters of a uniform control system.
3. Explain how a cascade control system compensates for nonlinear characteristics.
4. How can an I/A Series system be designed?
5. What are the key considerations for routine software maintenance in an I/A Series system?
6. Analyze the similarities and differences between the CALC module and the CALCA module in an I/A Series system. 7. Briefly describe the 3-layer communication network structure of the WebField ECS-100 system. 8. In chemical enterprises, there is a type of locator known as the 7400 series, whose schematic is shown in the figure. Based on the guidelines, describe its working principle by combining it with the feedback principle of valves/positioners. 9. Describe the working principle of the valve positioner as shown in the figure. 10. Describe the process of leveling the base and securing it in place. 11. Describe the requirements for the installation of electric actuators. 12. Briefly outline the three main structural forms of microcomputer distributed control systems, and explain the structural characteristics of each form. 13. Describe the methods of making holes in a disc, and draw a simple diagram. 14. Describe the requirements that ladders must meet when in use

Is it this? If so, I’ll paste the answer here

Reply to 2# NEWAUTO: Hello, friend. I just registered on this website today, and I’m honored to come across your articles – they are truly very useful for those of us in the instrumentation field. Could you please send me the answers? ? ? Thank you so much! ! ! ! ! ! ! ! ! ! !