求一段自动化专业文字的英文翻译，翻得好追加分~！ Boiler drum water level is in need of monitoring and control is an important parameter，which directly influence the safety and economic behavior of boiler operation.Based on the method of commonly used drum water level measurement based on the comparison and analysis of the differential pressure water meter principle，basic structure and the existing problems.According to the water pressure difference in design，existing problems in existing basis and made reliable differential pressure type water meter design.Design of type measuring system，including water balance container structure，use instrument selection，compensation，and the formula of fitting with DCS configuration to realize the determination of water.As the fitting method，the formulas are also use matlab this mathematical tool.With the two methods，namely simulink7.1 simulation and DCS(results-related areas-90)realized the final determination of drum water level.
为什么就地水位计的零水位线应比汽包内的零水位线？为什么就地水位计的零水位线应比汽包内的零水位线低？
双色水位计用哪个字母表示？用U表示趴
