Operational Theory; Zro 2 Sensor; Introduction; Principles Of Operation - Teledyne 3000ZA Operating Instructions Manual

Trace oxygen analyzer

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Operational Theory

The analyzer is composed of three subsystems:

1. Zirconium Oxide (ZrO

2. Sample System

3. Electronic Signal Processing, Display and Control

The sample system is designed to accept the sample gas and

transport it through the analyzer without contaminating or altering the

sample prior to analysis. The ZrO

amount of oxygen present in the sample into an electrical current. The

electronic signal processing, display and control subsystem simplifies

operation of the analyzer and accurately processes the sampled data. The

microprocessor controls all signal processing, input/output and display

functions for the analyzer.

2.2 ZrO

Sensor

Teledyne's zirconium oxide sensor is a miniature solid state sensor.

It uses a stabilized zirconia disc as an electrolyte with a sensing

electrode (the cathode) and a counter electrode (the anode) on each side

of the disc. The zirconia is heated to a temperature of about 500°C via a

built-in heater. By applying a suitable reference voltage (approximately

0.75 volt) across the cathode and anode, the heated zirconia acts as an

electrolyte which is capable of moving oxygen ions within its crystalline

structure. This allows for the reduction of oxygen molecules reaching

the cathode and the generation of a current equivalent to the parts per

million oxygen in the sample gas.

This sensor has been modified to sense low levels of oxygen—less

than 1 ppm and generate a current proportional to the concentration. The

sensor is designed for long term stability and an operating life of 5 years.

Teledyne Analytical Instruments

) Sensor

sensor is a device that translates the

3000ZA

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