G405 Series

Zirconia Oxygen Analyser

Zirconia analyser for ppm or % Oxygen measurements in non-combustible & inert stream gas.

The G405 is an extractive Zirconia analyser housed in a rack 19” case, typically used for in line O2 traces measurements in pure gas or in flue gas. Also available in transportable benchtop case.

Measureable Gas

Oxygen [O2]

Main Features

Two Versions

  • Version with solid state reference sensor (micro-pod) for general purpose applications
  • Version with reference air system for low trace O2 and O2 purity measurements

Extreme Roughness

  • No inner moving parts
  • Installation position and vibration don’t alter the accuracy and stability of the measure
  • For version with reference air system: completely insensitive to very wide barometric variations

High Performances

  • Extremely fast response time
  • Excellent long term stability
  • Inner reference air that eliminates the effect pf barometric pressure variations
  • All parts wetted by gas “Grease Free” for O2 purity applications
  • Ranges from 10 ppm O2 FS up to 100% O2 FS

European Compliance

  • Low Voltage Directive 2014/35/EU
  • EMC Directive 2014/30/EU


Oxygen purity monitoring

In line measurements of trace O2 in pure, inert gases (purity monitoring of N2, Ar, He, CO2)

Air Separators

Nitrogen and Oxygen Generators

Heat treatments



Welding Gas

Combustion Gas

Endothermic Generators

ppm or % O2 measurement in every process with non-combustible background gas

Inerting circuits with not combustible gases

Trace measurements in semiconductors industry

Pure Oxygen measurements on Aircrafts and molecular sieves generators

Sampling System

The G405 needs an external sampling system able to deliver an almost clean sample gas to the analyser at the proper temperature, pressure and flow rate.

The instrument can integrate some sampling components like filters, pumps, flow meters, pressure reducers, etc… being configured as a compact as analysis system itself and can be used for continuous measurements where process conditions are nor extremely severe (in this case a proper external sample and conditioning system is required).

ADEV has a wide experience in process and can provide the G405 analyser combined with a sample and condition system designed for the specific application requirements. Contact ADEV for details


Measuring Principle

 The measuring principle on which the analysis is based is linked to the use of Zirconium oxide which, at high temperatures, can behave like a solid state electrolyte, developing an electromotive force on two electrodes placed in contact with different O2 concentrations (partial pressures), proportional to the temperature in Kelvin degrees (°K) and the logarithm of the ratio between the two pressures PO2’ and PO2” in accordance with Nernst’s well-know ratio:


E = RT / nF (Lg P02’ / P02“)


Where:           R = Perfect gas constant (8,31 Joule/degree bulk)

                       F = Faraday’s constant

                       T = Absolute temperature in °Kelvin

                       n = 4