Реферат

This practice describes the photomultiplier properties that are essential to their judicious selection and use of in emission and absorption spectrometry. The properties covered here include structural features, electrical properties, and characteristics involved in precautions and problems. The structural features covered are envelope configurations, window materials, electrical connections, and housing for the external structure, and the photocathode, dynodes and anode, and rigidness of structural components for the internal structure. Electrical properties, on the other hand, incorporate the following: optical-electronic characteristics of the photocathode including spectral response; current amplification including gain per stage, overall gain, gain control (voltage-divider bridge), linearity of response, and anode saturation; signal nature; dark current including cathode size, internal aperture, and refrigeration effects; noise nature including additivity of noise power, signal-to-noise ratio, equivalent noise input; and photomultiplier properties as a component in an electrical circuit including output impedance, response time, and signal gating and integration possibilities. Finally, the characteristics involved in precautions and problems cover fatigue and hysteresis effects, illumination of photocathode, and gas leakage.

Область применения

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

Section Structural Features4 General4.1 External Structure4.2 Internal Structure4.3 Electrical Properties5 General5.1 Optical-Electronic Characteristics of the Photocathode5.2 Current Amplification5.3 Signal Nature5.4 Dark Current5.5 Noise Nature5.6 Photomultiplier as a Component in an Electrical Circuit5.7 Precautions and Problems6 General6.1 Fatigue and Hysteresis Effects6.2 Illumination of Photocathode6.3 Gas Leakage6.4 Recommendations on Important Selection Criteria7

1.2 Radiation 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.

1.3 This 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.