119
Metrological certificate of approval
Information on DrägerSensor O
2
(6809720)
Principle of measurement: The DrägerSensor O
2
(6809720) is an electrochemical two-electrode-sensor for measurement of oxy-
gen (O
2
) in air. The sensor can only be operated in connection with a suitable Dräger transmitter.
Reaction at the measuring electrode: O
2
+ 2 H
2
O + 4 e
–
=> 4 OH
–
Reaction at the counter-electrode: 2 Pb => 2 Pb
2
+ + 4 e
–
Ambient conditions:
Operational Characteristics –5
o
C to 40
o
C, temporarily –20
o
C to 55
o
C
700 hPa to 1300 hPa
10 to 95 % relative humidity, non condensing
Storage 0
o
C to 40
o
C
700 hPa to 1300 hPa
30 to 70 % relative humidity, non condensing
Measured value time setting:
t
0...20
<12 seconds
t
0...90
<30 seconds
Note: In the case of temperatures below –5
o
C, the measured value time setting may increase.
Calibration:
Flow rate: 0.5 L/min
Zero gas Nitrogen (99.9 Vol.-% N
2
)
Calibration gas Oxygen / nitrogen – mixed gas
Warming-up time:
Sensor is ready to operate after ≤15 minutes
Sensor is ready to calibrate after ≤2 hours