Teledyne 3010TAC - Split architecture trace oxygen analyzer (EU - CENELEC) - Manual (Page 65)

Part II: 2-1
Oxygen Analyzers Part II: Analysis Units
Teledyne Analytical Instruments
Operational Theory
2.1 Introduction
The Analysis Unit is composed of two subsystems: the Micro-Fuel
Cell sensor and the sample system.
The Micro-Fuel Cell is an electrochemical galvanic device that trans-
lates the amount of oxygen present in the sample into an electrical current.
The sample system is designed to accept the sample and calibration gasses,
select between them (in response to Control Unit signals), and transport the
gas through the analyzer—without contaminating or altering its composi-
tion before it reaches the sensor.
The electronic signal processing, display, and control systems are
housed in the remote Control Unit, covered in Part I of this manual.
2.2 Micro-Fuel Cell Sensor
2.2.1 Principles of Operation
The oxygen sensors used in the Model 3010TAC series are Micro-
Fuel Cells designed and manufactured by Analytical Instruments. They are
sealed plastic disposable electrochemical transducers.
The active components of a Micro-Fuel Cell are the cathode, the
anode, and the 15% aqueous KOH electrolyte in which they are immersed.
The cell converts the energy from a chemical reaction into an electrical
current in an external electrical circuit. Its action is similar to that of a
battery.
There is, however, an important difference in the operation of a
battery as compared to the Micro-Fuel Cell: In the battery, all reactants are
stored within the cell, whereas in the Micro-Fuel Cell, one of the reactants
(oxygen) comes from outside the device as a constituent of the sample gas