1.1This practice covers photomultiplier properties that are essential to their judicious selection and use in emission and absorption spectrometry. Descriptions of these properties can be found in the following sections:

	Section
Structural Features	4
General	4.1
External Structure	4.2
Internal Structure	4.3
Electrical Properties	5
General	5.1
Optical-Electronic Characteristics of the Photocathode	5.2
Current Amplification	5.3
Signal Nature	5.4
Dark Current	5.5
Noise Nature	5.6
Photomultiplier as a Component in an Electrical Circuit	5.7
Precautions and Problems	6
General	6.1
Fatigue and Hysteresis Effects	6.2
Illumination of Photocathode	6.3
Gas Leakage	6.4
Recommendations on Important Selection Criteria	7

1.2Radiation in the frequency range common to analytical emission and absorption spectrometry is detected by photomultipliers presently to the exclusion of most other transducers. Detection limits, analytical sensitivity, and accuracy depend on the characteristics of these current-amplifying detectors as well as other factors in the system.

1.3This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.