8864

Zirconia Oxygen Analyser

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

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

                  IP65

 

ATEX Certificate Number CESI 03 ATEX 130

Specification

Performance
Accuracywith 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).
Linearitybetter than ± 1% of full scale
Response TimeInitial < 0.1 sec.; 90%: < 1 sec. (with max. 1500 cc/min. flow rate)
DriftZero: max. ± 1% of span per week
Ambient Temp. Influencemax. ± 0.06% of reading per °C
Atm. Pressure Influence1% of reading per 1% change in ambient pressure
Flow Rate Influenceless than 0.5% of span over flow range of 250 to 1000 cc/min.
Line Voltage Influencemax. 0.02% of span, for each 1% change of power voltage.
Gas Interferencecombustible gases + O2 reduce the measure
Operative
Sample RequirementsFlow Rate: 250 ÷ 1000 cc/min.
Pressure: 3000 Pa minimum (with filter and flow meter).
RangeRefer to ordering information
OutputStandard 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 Humidity90% maximum.
Operation Temperature-10 ÷ +50°C (14 to 122 °F).
Temperature controlledat 720°C
Storage Temperature+70°C (158 °F) max.
Power Requirements22 ÷ 30 Vac, 50 VA from dedicated power supplier.
Pneumatic Connections¼” or 6 mm OD tubing (compression fittings supplied)
Wiring ConnectionsGeneral purpose: 2 openings for G 3/8" (PG 13 cable grip).
Ex-Proof: 2 openings for GK 1/2" (cable grip or conduit).

Applications

 

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

Air Separators

Nitrogen Generators

Heat treatments

Mixers

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 analyser at the proper temperature, pressure and flow rate.

ADEV has a wide experience in process and can provide the 8864 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

 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.

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