象增强器的一个最重要的特性,是能够探测微弱的信号。因为被探测辐射及电子发射的统计性会产生一个噪声背景,所以,要在该噪声背景上区分出相邻的两个景元间的亮度差,就是一个困难的问题。在此,我们须指出,任何仪器的本身,都是一个附加的噪声源,这就使仪器输出的信噪比降低: One of the most important features of image intensifiers is the ability to detect weak signals. Because the statistical nature of the detected radiation and the electron emission produces a noisy background, it is a difficult problem to distinguish the difference in luminance between two neighboring elements on the noisy background. Here, we must point out that any instrument itself is an additional source of noise, which reduces the signal to noise ratio of the instrument output: