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基于DDS的民航飞机选择呼叫发射机研制 被引量:1
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作者 张鹏 段照斌 《测控技术》 CSCD 北大核心 2013年第3期106-110,共5页
选择呼叫发射机主要用于飞机选择呼叫系统的测试,需要按照测试要求产生与实际相符的信号。系统采用DDS技术,设计选择呼叫信号的数字合成、载波信号频率控制和调幅射频放大3部分电路,并将其集成到系统内部,是一套完整的选择呼叫信号发射... 选择呼叫发射机主要用于飞机选择呼叫系统的测试,需要按照测试要求产生与实际相符的信号。系统采用DDS技术,设计选择呼叫信号的数字合成、载波信号频率控制和调幅射频放大3部分电路,并将其集成到系统内部,是一套完整的选择呼叫信号发射机。研制的系统实验指标达到设计标准,产生的信号准确稳定,能够按照设定同时发送3路甚高频选择呼叫射频信号,可以直接用于对飞机选择呼叫接收机的测试。 展开更多
关键词 DDS技术 选择呼叫 航空器测试
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Discussion on National Standard GB 6167"Methods for Testing the Performance of Airborne Particle Counter
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作者 刘俊杰 朱能 王君山 《Transactions of Tianjin University》 EI CAS 2003年第2期153-156,共4页
Airborne pa rt icle counters are used widely to test the air cleanliness of cleanrooms. The cur rent Chinese national standard of airborne particle counter calibration, GB6167 -85, Methods for Testing the Performance ... Airborne pa rt icle counters are used widely to test the air cleanliness of cleanrooms. The cur rent Chinese national standard of airborne particle counter calibration, GB6167 -85, Methods for Testing the Performance of Dust Particle Counter, has kept the same for more than 10 years. It is necessary to be amended in time. This paper discusses the differences between Chinese airborne particle counter calibration procedure and other new calibration procedures in other countries, and points ou t the defects of current Chinese national standard.The draft of revised Chinese National Standard is also introduced. The new revised standard, Methods for Test ing the Performance of Airborne Particle Counter, covers two level calibrations: primary and secondary. Primary calibration procedure includes testing 6 kinds of performances:sample airflow rate, false counting, particle size accuracy and re solution, particle counting stability, counting efficiency and particle concentr ation limit. Secondary calibration is a relative comparing test method to verify the counting accuracy of calibrated airborne particle counters.Finally, how to keep the calibration traceability is suggested. 展开更多
关键词 AEROSOL airborne particle counter (AP C) particle calibration procedure national standard
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