Teledyne 6020 - Photometric analyzer - Manual (Page 63)

Part II: 1-1
Photometric Analyzer Operational Theory 1
Teledyne Analytical Instruments
Operational Theory
1.0 Introduction
The Teledyne Photometric Analyzer uses the ultraviolet (UV) absorp-
tion principle to detect and continuously measure a component of interest in
a sample stream. The analyzer consists of a single sample cell, chopped beam,
dual-wavelength UV process photometer and associated microprocessor
based control unit and electronics.
1.1 Method of Analysis
The following description shows the course of optical energy in the
analyzer. The optical energy is emitted from a source lamp in the source
module, passed through the sample cell, and received by the sensor, which
converts the optical energy to pulses of electrical energy. These pulses of
electrical energy are processed further in the detector module.
The result is separate pulses that are compared in the control unit to
reveal the measurable difference between optical absorption of the sample at
a selected wavelength (determined by the measuring optical filter) and a zero-
absorption condition (set by the reference optical filter). The magnitude of that
difference represents the concentration of the component of interest in the
sample.