Teledyne 3000ZA Operational Theory, Introduction, ZrO2 Sensor, Principles of Operation

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Operational Theory

3000ZA

 

 

 

Operational Theory

2.1 Introduction

The analyzer is composed of three subsystems:

1.Zirconium Oxide (ZrO2) Sensor

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 ZrO2 sensor is a device that translates the 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 ZrO2 Sensor

2.2.1 Principles of Operation

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

0.75volt) 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

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Contents Model 3000ZA 3000ZA Specific Model Information Important Notice Safety Messages 3000ZA Vii Table of Contents Maintenance OperationAppendix IndexList of Figures Model 3000ZA Front PanelList of Tables Main Features of the Analyzer IntroductionOverview Typical ApplicationsModel Designations Introduction 3000ZAFront Panel Operator Interface Model 3000ZA Front PanelIntroduction 3000ZA Rear Panel Equipment Interface Model 3000ZA Rear PanelPower Connection Universal AC power source Scheduled calibrations can vary 2-3 % per day Operational Theory IntroductionZrO2 Sensor Principles of OperationSample System Model 3000ZA Sample SystemElectronics and Signal Processing Zirconium Oxide Sensor Application NotesTrace Oxygen Analyzer Operational Theory Component Location Electronic Block Diagram Mounting the Analyzer InstallationUnpacking the Analyzer Trace Oxygen Analyzer Installation Rear Panel Connections Gas ConnectionsSample Primary Input Power Electrical ConnectionsEquipment Interface Connector Pin Arrangement Analog Output Connections Alarm Relay Contact Pins Remote Calibration Connections Range ID Relay Connections Remote Probe Connections Commands via RS-232 Input 2.3 RS-232 PortInstalling the Zirconium Oxide Sensor Testing the SystemTrace Oxygen Analyzer Installation Operation Using the Data Entry and Function Buttons Hierarchy of Available Functions System Function TRAK/HLD Auto-Cal Pswd Logout More Setting up an Auto-Cal Password Protection Pswd Restrictions Removed Retype PWD To Verify System Self-Diagnostic Test LogoutVersion Screen Showing Negative Oxygen ReadingsZero and Span Functions Zero Cal Zero Settling Man ENT To Begin Span Cal #### ppm Span Slope=#### ppm/s Span Failure Alarms Function AL-1 AL-2 Choose Alarm Setting the Analog Output Ranges Range FunctionFixed Range Analysis Signal Output Analyze FunctionRange ID Output Voltage Page Maintenance Routine MaintenanceCell Replacement Removing the SensorFuse Replacement Trace Oxygen Analyzer MaintenanceSystem Self Diagnostic Test Installing FusesMajor Internal Components Rear Panel Removal Remove only those screws marked with anCleaning TroubleshootingIf erratic behavior Specifications AppendixTrace Oxygen Analyzer Appendix Recommended 2-Year Spare Parts List Drawing List 19-inch Relay Rack Panel MountApplication Notes Flow Rate RecommendationsBY-PASS Conversions PSI Scfh = 0.476 Slpm Index Trace Oxygen Analyzer Index Relay connections, 22 relay contacts Trace Oxygen Analyzer Index Teledyne Analytical Instruments