Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 133)

IM 11M12A01-05E 10-6
10.1.15 Robustness of a Cell
The robustness of a cell is an index for predicting the remaining life of a sensor and is
expressed as one of four time periods during which the cell may still be used:
(1) more than a year
(2) more than six months
(3) more than three months
(4) less than one month
The above four time periods are tentative and only used for preventive maintenance, not
for warranty of the performance.
This cell’s robustness can be found by a total evaluation of data involving the response
time, the cell’s internal resistance, and calibration factor. However, if a zero or span
calibration was not made, the response time cannot be measured. In such a case, the
cell’s robustness is found except for the response time.
Table 10.3 Cell Robustness and Service Life
Cell robustness Cell s service life
5 One year min.
3 Six months min.
2 Three months min.
1 One month max.
T10.3.EPS
10.1.16 Heater On-Time Ratio
The probe sensor is heated to and maintained at 7508 C. When the measured gas tem-
perature is high, the amount of heater ON-time decreases.
10.1.17 Oxygen Concentration (with time constant), Humidity (with time constant), and
Mixing Ratio (with time constant)
When the output damping is specified in the mA-output range setting, the corresponding
time constant is also displayed.
10.1.18 Maximum Oxygen Concentration, Humidity, and Mixing Ratio
The maximum oxygen concentration and the time of its occurrence during the period
specified in the Averaging display are displayed. If the setup period elapses, the maxi-
mum oxygen concentration that has been displayed so far will be cleared and a new
maximum oxygen concentration will be displayed. If the setup period of time is
changed, the current maximum oxygen concentration will be displayed (for more details,
see Section 8.6.2 earlier in this manual).
10.1.19 Minimum Oxygen Concentration, Humidity, and Mixing Ratio
The minimum oxygen concentration and the time of its occurrence during the period
specified in the Averaging display are displayed. If the setup period elapses, the mini-
mum oxygen concentration that has been displayed so far will be cleared and a new
minimum oxygen concentration will be displayed. If the setup period of time is changed,
the current minimum oxygen concentration will be displayed (for more details, see
Section 8.6.2 earlier in this manual).