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Electrochemical oxygen sensor
Measurement principle
Electrochemical oxygen sensor
Sample component and measurement range
Sample component
Oxygen (O
)
2
Smallest measurement range
0–5 vol.-% O
2
Measurement range
Factory-set to 0–25 vol.-% O
Adjustable from 0–5 vol.-% O
Stability
Linearity deviation
Linear in the range > 1 vol.-% O
Repeatability
≤ 0.5 % of span
Zero drift
Stable over long-term due to absolute zero point
Sensitivity drift
≤ 1 % of the measurement range per week
Output fluctuation (2 σ)
≤ 0.2 % of the measurement range at electronic T90 time
(static / dynamic) = 5 / 0 sec
Detection limit (4 σ)
≤ 0.4 % of the measurement range at electronic T90 time
(static / dynamic) = 5 / 0 sec
Influence effects
Flow effect
Flow rate in the 20–100 l/h range:
≤ 2 % of the measurement range
Temperature effect
Ambient temperature in the +5 to +40 °C range:
≤ 0.2 vol.-% O
per 10 °C
2
Air pressure effect
– At zero-point: No effect
– On sensitivity with no pressure correction:
≤ 1 % of measured value per 1 % air pressure change
– On sensitivity with pressure correction:
≤ 0.2 % of sample value per 1 % air pressure change
Pressure correction is only possible if the oxygen sensor is
connected to the Uras26 infrared photometer with an
integral pressure sensor.
Power supply effect
Voltage and frequency in the permissible range: ≤ 0.2 % of
span
14
.
2
to 0–25 vol.-% O
2
2
2
EasyLine EL3000 Series Data Sheet
Dynamic response
90% response time
≤ 30 sec at sample gas flow of 60 l/h and electronic
T
90
T90 time (static / dynamic) = 5 / 0 sec
Calibration
Zero-point calibration
The oxygen sensor zero is not calibrated since it is
fundamentally stable.
End-point calibration
With ambient air at 20.96 vol.-% O
Materials in contact with the sample medium
Sensor
Polystyrol-ABS, PTFE, FPM (Fluorocarbon rubber)
Housing body
PVC, FPM (Fluorocarbon rubber) seals
Gas ports
Stainless steel 1.4571 (SAE 316Ti)
Gas inlet conditions
The oxygen sensor must not be used for measurement of
flammable gases and ignitable gas/air or gas/oxygen mixtures.
Temperature
The sample gas dew point should be at least 5 °C below the
temperature throughout the sample gas path. Otherwise a
sample gas cooler or condensate trap is required.
Moisture content
O dew point ≥ 2 °C
H
2
The oxygen sensor should not be used with dry sample gas.
Inlet pressure
p
= 2–500 hPa
e
Outlet pressure
Atmospheric pressure
Flow rate
20–100 l/h
Associated gas
The oxygen sensor must not be used if the associated gas
contains the following components: H
compounds, heavy metals, aerosols, mercaptans, and base
components.
Note
The electrochemical oxygen sensor can only be used in combi-
nation with Uras26 or Limas23. It cannot be used when the
internal gas lines in the Uras26 are made up of stainless steel or
PTFE pipes.
2
S, chlorine or fluorine
2
10/24-4. 1 0 EN Rev. 9
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