34
A-96.250.701 / 140716
AMI INSPECTOR Oxygen
Maintenance
6.5
Zero-Verification
Swansensor Oxytrace G for the measurement of low oxygen con-
tent (< 1 ppb).
1
Calibrate the sensor according to chapter
Calibration, p. 32
.
2
Prepare a 5%-sodium sulfite solution with demineralized water.
3
Put the electrode into the sodium sulfite solution afterwards. As-
sure that there are no air bubbles in front of the sensor.
4
The measured value should now be < 1 ppb.
NOTICE:
Depending on the state of the electrode this process
can take several hours. In case of an electrode-refill, this can
take days until the measured value is lower than 1 ppb.
6.6.
Quality Assurance of the Instrument
Every SWAN on-line instrument is equipped with integrated, auton-
omous quality assurance functions to survey the plausibility of each
measurement.
For the AMI Oxytrace / AMI Oxytrace QED these are:
continuous monitoring of sample flow
continuous monitoring of the temperature inside the transmit-
ter case
periodic accuracy test with ultra high precision resistors
Further a manual, menu driven inspection procedure can be carried
out using a certified reference instrument. Running at the same
sampling point as an inspection equipment, the AMI Inspector Oxy-
gen verifies the measuring results. After enabling the quality assur-
ance procedure by defining the quality assurance level, the
instrument reminds the user periodically to run the procedure and
results are stored in a history for review.
Quality
assurance
level
Central feature of the quality assurance function is the assignment
of the monitored process to a Quality assurance level.
There are three predefined levels plus a user level. Hereby the in-
spection interval, the deviation limits of temperature and measuring
result between the inspection equipment and the monitoring instru-
ment are defined.