【Daily Question 20090307】Several multiple-choice questions on stepwise adjustment
Thread Content
1. In a step-controlled system, the segmentation of the signal ranges for the two valves is achieved by ( ). A. Regulator B. Electrical converter C. Valve positioner D. Transmitter 2. Split-range control is applied in ( ). A. Expanding the adjustable range of the control valve. B. Meeting process requirements for controlling two different media in one control system. C. Being used for processes with large amplification factors. D. Safety measures for production. E. Being used for processes with high time lags. 3. A multi-stage control system generally has （） control valves. ①1 ； ②2 ； ③3 ； ④4 Answers: 1. C 2. ABD 3. ② Last edited by Mobei Yihai on 2009-3-7 20:27 ]
1. In a step-controlled system, the segmentation of the signal ranges for the two valves is achieved by (C). A. Regulator B. Electrical converter C. Valve positioner D. Transmitter 2. Split-range control is applied in (ABD). A. Expanding the adjustable range of the control valve. B. Meeting process requirements for controlling two different media in one control system. C. Being used for systems with large amplification factor variations. D. Safety measures for production. E. Being used for systems with large time lags. 3. A split-range control system generally has (②) control valves. ①1 ； ②2 ； ③3 ； ④4
Answer: 1, C; 2, CDE; 3,②
A control system that uses the output of a controller, in conjunction with valve positioners, to control two or more control valves in segments is called a split-range control system. A proportional control system is one in which a controller operates two or more control valves, with each valve acting within a certain signal range provided by the controller according to the process requirements. The purpose of setting stepwise adjustment is to expand the adjustable range and meet the special requirements of the process. It can improve the control quality and the operating conditions of control valves ； It meets the requirements for low flow rates during startup and shutdown, as well as high flow rates during production, ensuring good control quality in all cases ； Ensure stability and safety under normal operation as well as in emergency conditions. 1. C valve positioner 2. ABD (A. Expanding the adjustable range of the control valve; B. Meeting process requirements for controlling two different media within one control system; D. Safety measures for production) 3. (2) Two control valves
1、C 2、ABD 3、②
1、C 2、ABD 3、②
1. In a step-controlled system, the segmentation of the signal ranges for the two valves is achieved by (C). A. Regulator B. Electrical converter C. Valve positioner D. Transmitter 2. Split-range control is applied in (ABD). A. Expanding the adjustable range of the control valve. B. Meeting process requirements for controlling two different media in one control system. C. Being used for systems with large amplification factor variations. D. Safety measures for production. E. Being used for systems with large time lags. 3. A split-range control system generally has (②) control valves. ①1 ； ②2 ； ③3 ； ④4
1、C 2、ABD 3、②
My answers: 1. C 2. ABD 3②
Layered adjustment allows for the control segmentation to be implemented not at the valve itself, but rather through software settings; this enables the range of the valve actuator to be uniformly set using 4-20mA signals
1.C 2.ABD 3.(2)
1.C 2.ABD 3.(2)
1,C 2,AD 3,2
1. In a step-controlled system, the segmentation of the signal ranges for the two valves is achieved by (C). A. Regulator B. Electrical converter C. Valve positioner D. Transmitter 2. Split-range control is applied in (ABD). A. Expanding the adjustable range of the control valve. B. Meeting process requirements by controlling two different media in one control system. C. Being used for systems with large changes in amplification factors. D. Safety measures for production. E. Being used for systems with high lag. 3. A split-control system generally has (②) control valves. ①1 ； ②2 ； ③3 ； ④4
1. The segmented signal range for the two valves in the step-controlled system is achieved by (C). A. Regulator B. Electrical converter C. Valve positioner D. Transmitter 2. Split-range control is applied in (ABD). A. Expanding the adjustable range of the control valve. B. Meeting process requirements for controlling two different media in one control system. C. Being used for systems with large amplification factor variations. D. Safety measures for production. E. Being used for systems with large time lags. 3. A split-range control system generally has (②) control valves. ①1 ； ②2 ； ③3 ； ④4
1、a 2、ABD 3、(2)
1、A 2、ABD 3、(2)
1. In a step-controlled system, the segmentation of the signal ranges for the two valves is achieved by (C.). C. Valve positioner 2. Split-range control is applied in (ABD). A. Expanding the adjustable range of the control valve. B. Meeting process requirements by controlling two different media in one control system. D. Safety measures for production. E. Used for systems with large time lags. 3. A split-control system generally has (2) control valves. ②2
1. In a step-controlled system, the segmentation of the signal ranges for the two valves is achieved by (C). A. Regulator B. Electrical converter C. Valve positioner D. Transmitter 2. Split-range control is applied in (ABD). A. Expanding the adjustable range of the control valve. B. Meeting process requirements for controlling two different media in one control system. C. Being used for systems with large amplification factor variations. D. Safety measures for production. E. Being used for systems with large time lags. 3. A split-range control system generally has (②) control valves. ①1 ； ②2 ； ③3 ； ④4
1. In a step-controlled system, the segmentation of the signal ranges for the two valves is achieved by (C). A. Regulator B. Electrical converter C. Valve positioner D. Transmitter 2. Split-range control is applied in (ABD). A. Expanding the adjustable range of the control valve. B. Meeting process requirements for controlling two different media in one control system. C. Being used for systems with large amplification factor variations. D. Safety measures for production. E. Being used for systems with large time lags. 3. A split-range control system generally has (②) control valves. ①1 ； ②2 ； ③3 ； ④4
1. In a step-controlled system, the segmentation of the signal ranges for the two valves is achieved by (C). A. Regulator B. Electrical converter C. Valve positioner D. Transmitter 2. Split-range control is applied in (ABD). A. Expanding the adjustable range of the control valve. B. Meeting process requirements for controlling two different media in one control system. C. Being used for systems with large amplification factor variations. D. Safety measures for production. E. Being used for systems with large time lags. 3. A split-range control system generally has (②) control valves. ①1 ； ②2 ； ③3 ； ④4