Siemens ULTRAMAT 23, Manual, Page: 106 / 244

Functions
8.1 Diagnostics
ULTRAMAT 23
106
Manual, 3/2016, A5E37100388-003
8.1.1.4 Analyzer status: Status: O2 sensor status
The probe voltage of the O
2
sensor is reduced during use due
to its aging process. Therefore the probe voltage is measured
with each AUTOCAL. A warning (maintenance request) is out-
put if the value drops below 6.0 mV. The oxygen sensor should
therefore be replaced when this value is reached. An exact
measurement is no longer possible if the probe voltage falls
below the minimum value of 5.0 mV (fault message "Sensitivity
of O
2
sensor too low").
• The reading (actual value) is the probe voltage measured
on the sensor during the last AUTOCAL.
•
The warning (maintenance request) and fault are the two
minimum values where a maintenance request or fault
message is output when fallen below.
8.1.1.5 Analyzer status: Status: H2S sensor status
The H
2
S sensor ages with increasing operating time, thereby
steadily decreasing its sensitivity. If a value below the mini-
mum value for a warning is determined during calibration of the
sensitivity, the service life of the sensor has almost been
reached (maintenance request). If the sensitivity drops further
below the value for a fault, the fault message "Sensitivity of
H
2
S sensor too low" is output. The sensor must then be re-
placed.
•
The reading (actual value) is the sensor sensitivity
measured during the last sensitivity calibration.
• The warning (maintenance request) and fault are the two
minimum values where a maintenance request or fault
message is output when fallen below.