【2025 Knowledge Accumulation】Questions 4–6 with Answers
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This post was last edited by The one on 2025-11-27 11:21. 4. To measure the negative pressure in a boiler furnace (i.e., pressure lower than atmospheric pressure), which device should be used? A. Absolute pressure transmitter B. Gauge pressure transmitter C. Differential pressure transmitter D. Sealed pressure transmitter Answer: B Reason: Measuring negative pressure (vacuum) essentially means measuring a pressure that is lower than the local atmospheric pressure. The low-pressure side of the gauge pressure transmitter is connected to atmospheric pressure, while the high-pressure side is connected to the pressure to be measured. When the pressure being measured is below atmospheric pressure, the gauge pressure transmitter will output a negative value or a signal below 4 mA (such as 3.6 mA).
5. Which of the following media cannot be measured by an electromagnetic flowmeter? A. Tap water B. Concentrated saltwater C. Industrial wastewater D. Saturated steam Answer: D Reason: Electromagnetic flowmeters are based on Faraday’s law of electromagnetic induction, and the fluid being measured must have a certain level of conductivity. Saturated steam is a non-conductive gas, so it cannot be measured. Tap water, saltwater, and wastewater all contain conductive ions that can be measured.
6. In PID parameter tuning, if the system response exhibits excessive overshoot, what is the most effective way to improve it? A. Increase proportional gain B. Decrease integration time C. Increase derivative time D. Decrease derivative time Answer: C Reason: Excessive overshoot is usually caused by the system responding too quickly, with inertia leading to overshoot. Increasing the differential time Td can enhance the differential effect, suppress trends in change, effectively reduce overshoot, and improve the dynamic performance of the system.
Below are the links to Siemens selection software for reference. (1) TIA_Selection_Tool_cloud (online cloud version) https://mall.industry.siemens.com/tst/#/Start
(2) TIA_Selection_Tool (offline standalone version) link: https://pan.baidu.com/s/1RnNeuZwyPdHaYUBT8aGrVA Extraction code: 1111
(3) TIA_Selection_Tool tutorial link: https://pan.baidu.com/s/1SJMVlsJUqrNDWdtkssMHHQ Password: 1111
(4) SIZER_V3.23 link: https://pan.baidu.com/s/1AC8dygWdfic8gqyACwbNPg Extraction code: 1111
(5) SIZER_V3.22 link: https://pan.baidu.com/s/1iFh9tnFqNskmLayP2P87qw Extraction code: 1111
(6) SIZER_V3.21 link: https://pan.baidu.com/s/1qlA2R4FMKoZGzHzOxpihPQ Extraction code: 1111
(7) SIZER_V3.20 link: https://pan.baidu.com/s/1rn8W4Zkr2G3t_Io9u3nKXA Extraction code: 1111
(8) SIZER_V3.19 link: https://pan.baidu.com/s/1bOkJLZR5kx_nsgfJ5Ht2Mg Extraction code: 1111