曾经有人指出,原则上有两个现象限制着光电测温仪器(光电高温计与光谱高温计)的灵敏阈:光束光子数的波动和辐射接受器的噪声。其中后一现象更重要。前一现象曾经由许多作者详细地研究过。当研究后一现象时,通常允许误差的存在,因为要将若干特殊情况下才具有的正确结论推 It has been pointed out that in principle there are two phenomena that limit the sensitivity thresholds of photoelectric thermometers (photoelectric pyrometers and spectrometer pyrometers): fluctuations in the number of photons in the beam and noise in the radiation receiver. The latter phenomenon is more important. The previous phenomenon has been studied in detail by many authors. When studying the latter phenomenon, errors are usually tolerated because the correct conclusion to be found in a few exceptional cases