YOKOGAWA EXAxt ZR22G, User Manual, Page: 149 / 211

<10. Other Functions>
10-2
IM 11M12A01-02E 16th Edition : Mar. 19, 2020-00
10.1.2 Cell Response Time
The cell’s response time is obtained in the procedure shown in Figure 10.3. If only either a zero-
point or span calibration has been carried out, the response time will not be measured just as it
will not be measured in manual calibration.
mA
90%
100%
The response time is obtained after the corrected calibration curve has been found. The response time
is calculated, starting at the point corresponding to 10% of the analog output up to the point at 90% of
the analog output span. That is, this response time is a 10 to 90% response.
10% of analog
output span
Five minutes maximum
Response time
Start calibration
Time
Calibration
complete
F10.3E.ai
Figure 10.3 Typical Response Time characteristic
10.1.3 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 response time is not used as
a factor in evaluating the cell’s robustness.
10.1.4 Cell Temperature
This displays the cell (sensor) temperature, which is determined from the thermocouple emf and
cold junction temperature. Normally it is 750°C.
10.1.5 C. J. Temperature
This indicates the detector terminal box temperature, which compensates for the cold junction
temperature for a thermocouple measuring the cell temperature. When the ZR22 Detector is
used, the maximum C. J. temperature will be 150°C. If the terminal box temperature exceeds
this, take measures to shield the terminal box from heat radiation.
The maximum C. J. temperature varies depending on the type of detector.