Teledyne 6600 manual Photometer, Source Module

1 Operational Theory Model 6600

1.6Photometer

The photometer modules are mounted on a BACKPLATE inside a NEMA Enclosure (See D-71055). Facing the mounted photometer, the source module is at the right top, the sample module is externally located in the folded optics loop, and the detector module is on the right bottom. A source power supply module is placed near the HG source module.

1.6.1 Source Module

Any one of three types of source modules may be used in your system. For oil in water applications the Source module contains a HG source within its ellipsoid reflector containing a lens and clamp to focus the lamp energy through the folded optical train.

The QI (Quartz-Iodine) and D2 (Deuterium Arc) sources are mounted in the source module which also contains the focusing lens.

The source power supply module provides power to the lamps. The source power supply module houses the power supply, a connector for an optional temperature controller to heat the sample cell, and an optional span filter power supply.

The Quartz-Iodine lamp power supply is a switching regulator that maintains a constant voltage (5 VDC) across the filament of the lamp. The lamp is incandescent. Its envelope is filled with a halogen to avoid sputtering of the filament, blackening the lamp envelope.

The D2 lamp power supply is a combination current and voltage regulator. It maintains a constant anode current in the D2 lamp and controls the voltage across the lamp’s cathode (filament).

When power is turned on, relay K1 is activated and applies 10 VDC across the filaments. After ionization of the Deuterium vapor, the lamp starts to conduct from cathode (filament) to anode. This causes K1 to deactivate and the filament voltage drops to 7 VDC, which is the operating voltage. The voltage from anode to cathode which was 365 V before ionization, drops to about 60 VDC after ignition. This is the operating voltage. A constant current of 350 mADC is the anode current.

The Deuterium arc lamp is employed with samples whose component of interest does not absorb at the high intensity peaks of the HG source emission spectrum. The Deuterium arc produces a broadband of energy (200 to 400 nanometer) in the UV spectrum.

1-6 Part II Teledyne Analytical Instruments