ADEV - Model 8864 -Zirconia Oxygen Analyzer

• Oxygen [O2]

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

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
• 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 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 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
• Mixers
• Welding Gas
• Combustion Gas
• Endothermic Generators
• Any application for ppm or % O2 measurement in inert gas or combustion gas

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.