Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 107)

<9. Calibration>
9-6
IIM 11M12A01-04E
9.2.1.4 Span gas Concentration
Set the oxygen concentration for span calibration. If instrument air is used as the span gas, enter 21
%O
2
.
When using the ZO21S Standard Gas Unit (for use of the atmospheric air as a span gas), use a hand-
held oxygen analyzer to measure the actual oxygen concentration, and then enter it.
CAUTION
(1) When instrument air is used for the span calibration, remove the moisture from the instrument air
at a dew-point temperature of -20°C and also remove any oily mist and dust from that air.
(2) If dehumidifying is not enough, or if foul air is used, the measurement accuracy will be adversely
affected.
9.2.1.5 Calibration Time
• When the calibration mode is in manual:
First set the hold (output stabilization) time. This indicates the time required from the end of
calibration to entering a measurement again. This time, after calibration, the measurement
gas enters the sensor to set the time until the output returns to normal. The output remains
held after completing the calibration operation until the hold (output stabilization) time elapses.
The calibration time set ranges from 00 minutes, 00 seconds to 60 minutes, 59 seconds. For
more details, consult Section 8.3,”Setting Output Hold.” When the calibration mode is in semi-
automatic, set the hold (output stabilization) time and calibration time. The calibration time is the
time required from starting the flow of the calibration gas to reading out the measured value. The
set calibration time is effective in conducting both zero and span calibrations. The calibration
time set ranges from 00 minutes, 00 seconds to 60 minutes, 59 seconds. Figure 9.4 shows the
relationship between the calibration time and hold (output stabilization) time.
Analog output remains hold
(when output remains hold)
Calibration start
(contact or switch input)
Span calibration
(span gas valve open)
Zero calibration
(zero gas valve open)
Analog output status
Calibration time
Calibration time
Hold (output stabilization)
time
F9.4E.ai
Figure 9.4 Calibration and Hold (Output stabilization) Time Settings
• When the calibration mode is in automatic:
In addition to the above hold (output stabilization) time and calibration time, set the interval, start
date, and start time.
Interval means the calibration intervals ranging from 000 days, 00 hours to 255 days, 23 hours.
Set the first calibration day and the start-calibration time to the start date and start time
respectively. After the first calibration is carried out, the next calibration will be executed
according to the preset calibration intervals.