回复 71# 桃花岛主
谢谢岛主，计算错了，失误失误。
回复 64# stone0371
4.2 断续干扰，家电中的断续干扰只有一个测试项目-喀呖声（click）。
click的定义是用幅值和频率来定义的一个测试项目，产生click的常见骚扰源是可复位温控器、自动程序控制器、可控硅等。其本质是电流的突然变化，起变化要满足click定义的幅值和时间的要求。
Click测试只有四个频点 0.15M/0.5M/1.4M/30M。测试方法有两种，一种是用示波器，一种是用集成的断续骚扰分析仪。目前后者用的较多。
4.2.1 The limits for discontinuous disturbance depend mainly on the character of the disturbance and on the click rate N as given in detail in 4.2.2 and 4.2.3.
No discontinuous disturbance limits apply in the frequency range 30 MHz to 1 000 MHz.
NOTE The level of disturbances below 30 MHz is interpreted as an indication for the level above 30 MHz.
在30M-1000M之间的click没有限值要求。
note中指明30M以下的click骚扰，可以代表高于30M以上的骚扰情况。
4.2.2 Frequency range 148,5 kHz to 30 MHz (terminal voltages)
4.2.2.1 The limits of Table 1 apply also to discontinuous disturbances from all equipment which produce:
a) disturbances other than clicks, or
b) clicks with a click rate N equal to or greater than 30.
Appliances as described in 4.2.3 are exempted.
NOTE Examples of discontinuous disturbances for which the limits for continuous disturbance apply are shown in
Figures 4a and 4b.
条款4.2.2.1讲的是，在什么情况下用table1中的限值来作为click的限值的情况。需要满足两个条件：
1、不满足click定义的非连续性干扰。
2、click率大于30的情况下，
关于用table1的限值来作为断续骚扰限值的例子，是在附录figure 4a和figure 4b中，见下图
figure 4a 和figure 4b
4.2.2.2 For discontinuous disturbance, the click limit Lq is attained by increasing the relevant limit L (as given in 4.1.1) with:
44 dB for N < 0,2, or
20 lg (30/N) dB for 0,2 ≤ N < 30
NOTE Examples of discontinuous disturbances which are classified as clicks are shown in Figures 3a, 3b and 3c.
See also Annex A, Table A.1 and Table A.2.
4.2.2.2是click限值计算的主要方法，分为两种情况
1、当click率N<0.2时，
Lq=L(连续限值)+44dB。
2、当click率0.2<=N<30时。
Lq=L（连续限值）+20lg（30/N）.
其中在第二种情况下，要用到上四分法。下面给大家提供上四分法的例子，在EN 55014-1的附录中大家可以这个例子，有了这个例子，大家对上四分法理解应该深刻了很多。
上四分法的计算例子part1
part 2
