500 1000 1500 2000 I Q E SUPPLY VOLTAGE (V) THBV4_0445EA Figure 4-45: Example of EADCI THBV4_0445EA 74 CHAPTER 4 CHARACTERISTICS OF PHOTOMULTIPLIER TUBES b) AC expression In low-level-light measurements, the DC components of dark current can be subtracted. The lower limit of light detection is determined
