Rugged Zirconia analyser for ppm or % Oxygen measurements in combustion & inert gas.

The instrument features a special Zirconium Oxide sensor with reference to the solid state (micro-pod technology) eliminating the need for a reference air flow.

The weatherproof and explosion proof 8864 is designed for field installation in the most severe conditions, minimizing the sample conditioning requirements


Measureable Gas

Oxygen [O2]

Main Features

Extreme Roughness

  • No inner moving parts
  • Installation position and vibration don’t alter the accuracy and stability of the measure
  • Insensitive to ambient temperature variations


High Performances

  • Extremely fast response time
  • Excellent long term stability
  • Sensing unit temperature controlled
  • Available as 4-20 mA transmitter or combined with a powerful microprocessor-based control unit


Easy Maintenance

  • Modular construction
  • Fast access to the inner PCB just unscrewing the housing cap
  • Possibility to remove the entire sensing unit from the housing just by unscrewing 2 screws and leaving her housing connected to the sampling system.


European Compliance

  • Low Voltage Directive 2014/35/EU
  • EMC Directive 2014/30/EU
  • Directive ATEX 2014/34/EU (optional)



ATEX certification for Zone 1 / Zone 21 with protection mode:

II 2 G D     Ex db IIC T6 Gb

Ex tb IIIC T85°C Db



ATEX Certificate Number CESI 03 ATEX 130


Accuracy with control unit: ± 1% of span or ± 1 ppm (whichever is worse)
transmitter: ± 2% of span or ± 0.05% O2 (whichever is worse)
Repeatability ± 0.5% of span (short term).
Linearity better than ± 1% of full scale
Response Time Initial < 0.1 sec.; 90%: < 1 sec. (with max. 1500 cc/min. flow rate)
Drift Zero: max. ± 1% of span per week
Ambient Temp. Influence max. ± 0.06% of reading per °C
Atm. Pressure Influence 1% of reading per 1% change in ambient pressure
Flow Rate Influence less than 0.5% of span over flow range of 250 to 1000 cc/min.
Line Voltage Influence max. 0.02% of span, for each 1% change of power voltage.
Gas Interference combustible gases + O2 reduce the measure
Sample Requirements Flow Rate: 250 ÷ 1000 cc/min.
Pressure: 3000 Pa minimum (with filter and flow meter).
Range Refer to ordering information
Output Standard 8864 sensor output: logarithmic 50 mV/decade
functioning as input of control unit that operates calculation,
linearization and retransmits the isolated output current.
Transmitter version: 4-20 mA proportional to ordered range; max.
load 500 Ω (or 350 Ω with galvanically insulated module)
Diagnostic NV Logical Output (non-valid) Logical Non Valid output from relay free contact. Normally supplied
in fail safe condition (triggered relay and closed contact if not in alarm). Can be modified in filed
Relative Humidity 90% maximum.
Operation Temperature -10 ÷ +50°C (14 to 122 °F).
Temperature controlled at 720°C
Storage Temperature +70°C (158 °F) max.
Power Requirements 22 ÷ 30 Vac, 50 VA from dedicated power supplier.
Pneumatic Connections ¼” or 6 mm OD tubing (compression fittings supplied)
Wiring Connections General purpose: 2 openings for G 3/8″ (PG 13 cable grip).
Ex-Proof: 2 openings for GK 1/2″ (cable grip or conduit).



Gas production industry (purity monitoring of N2, Ar, He, CO2)

Air Separators

Nitrogen Generators

Heat treatments


Welding Gas

Combustion Gas

Endothermic Generators

Any application for ppm or % O2 measurement in inert gas or combustion gas

Sampling System

The 8864 needs an external sampling system able to deliver an almost clean sample gas to the analyzer at the proper temperature, pressure and flow rate.

ADEV has a wide experience in process and can provide the 8864 analyzer combined with a sample and condition system designed for the specific application requirements. Contact us 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

The inner sensing element is a based on a proprietary ADEV technology (micro-pod) and features a solid state reference that completely eliminate the need of a reference air flow, making the instrument very easy and practical to use in field.