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JJG307-1988(交流电度表(电能表)》明确规定,无论是单相电能表还是运行在平衡负载下的三相有功或无功电能表,其负载功率因数cosφ或sinφ中的φ,均指同一相的相电流与相电压的相位差。但是.当负载不平衡时,即分组检定时,相关元件的负载功率因数应改用cosQ或sinQ表示,其中Q是指加在同一组元 相似文献
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指出了电子式无功电能表没有对应的检定规程,提出了检定电子式无功电能表时,判定合格与否的基本误差限,以及测定基本误差应调定的负载功率。 相似文献
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本文主要介绍电能表的分类及感应式单相电能表、电子式单相电能表的工作原理,简述单相复费率电能表的工作原理及优点。笔者根据多年电能表校正理论和实际经验,总结了正确使用电能表检定装置时应注意的问题与常见故障及其排除方法,供读者参考。 相似文献
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随着家庭用电量日趋增大,家用电能表的误差正越来越被人们所重视。由此引起的经济纠纷也时有发生。从目前苏州市计量测试研究所对家用电能表的检定情况看,合格率很低。如今年7月初我们受台墅村委会委托,对该村的512台单相电能表进行检定,合格率仅为20%,不合格的410台中严重超差的有256台,占总量的50%。从检定情况看,引起电能表超差的原因主要有:1.由于安装使用后一直没有检定,长期使用而得不到应有的维护保养。按照JJG30Y7-1988电能表检定规程要求,对单宝石轴承的生活用单相电能表的检定周期不得超过5年,而实际上这类电表安… 相似文献
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在电能表检定收费过程中,湖北省鄂州市计量测试所执行的是湖北省鄂价费字[1997]154号文件的收费标准。但是在实际工作中,三相电能表收费标准不尽合理,比如检定一只2.0级安装式单相电能表,检定规程要 相似文献
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4月15日,科陆电子发布新产品上市公告。公告称。国内最大的单相智能电能表全自动检定系统产品日前在公司龙岗工业园电能表生产车间正式投入使用,该系统能实现日检定9000台智能电能表的能力,为国内单线配置表位最多、检定能力最强的系统产品,标志着该公司自主研发的CL1000AT单相智能电能表全自动检定系统产品正式投入市场。 相似文献
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《IEEE transactions on instrumentation and measurement》1984,33(3):147-154
Automatic test systems are described that are used to characterize and verify the output level performance of signal generators using internally stored correction data applied under microprocessor control. The characterization technique allows user verification of output level performance by direct measurement with a conventional power meter. Particular emphasis is given to a level verification system capable of measuring output power from +20 dBm to less than -140 dBm in a frequency range of 100 kHz to 2.5 GHz with an uncertainty of less than 1 dB. An analysis of error factors and actual performance data is presented. 相似文献
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The effects of backward, forward, and bidirectional Raman pumping schemes on stimulated Brillouin scattering (SBS) is investigated in this study. By using a linear cavity, we utilize residual Brillouin pump (BP) and Raman pump (RP) power after each transmission through a 25 km single-mode fiber (SMF) used as a gain medium. The SBS threshold power is reduced in the forward, backward, and bidirectional Raman pumping schemes by 2.5, 1.75, and 2.75 dB, respectively when the 1480 nm RP power is fixed at 150 mW and the BP wavelength is 1580 nm. Surprisingly, it is revealed that the SBS threshold reduction depends strongly and solely on Raman gain and it is independent of the Raman pumping schemes. In addition, the effect of Raman amplification on SBS is more effective at the SBS threshold, especially in the bidirectional and forward schemes. 相似文献
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本文介绍采用IC仿真卡技术,实现由公用电话的IC卡插口进行快速检定的方法、原理和软硬件设计。解决了IC卡公用电话检定需电信部门到现场配合拆机的技术难题。研究成功的多功能电话计费器检定仪可以检定各类公用电话。 相似文献
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《IEEE transactions on instrumentation and measurement》1980,29(1):71-73
This paper describes a design and the characteristics of a new optical power meter for 0.8-?m wavelength region optical fiber transmission systems. Features of this optical power meter are high sensitivity (-80 dBm), high stability (±0.005 dB at > -65 dBm), and small deviation against the plug rotation inside the receptacle (±0.02 dB). The SNR design method presented is useful in high sensitivity and high stability optical power meter design. 相似文献