Zero Gas Concentration; Span Gas Concentration; Calibration Time - YOKOGAWA ZR402G User Manual

9.2.3

Zero gas Concentration

Set the oxygen concentration for zero calibration. Enter the oxygen concentration for the zero
gas in the cylinder used.
9.2.4

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.
NOTE
• 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.
• If dehumidifying is not enough, or if foul air is used, the measurement accuracy will be
adversely affected.
9.2.5

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 8.2,"Output Hold Setting." 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 9.7 shows the relationship between the calibration time and
hold (output stabilization) time.
Calibration start
(contact or switch input)
Span calibration
(span gas valve open)
Zero calibration
(zero gas valve open)
Analog output status
Figure 9.7
Calibration time
Analog output remains hold
(when output remains hold)
Calibration and Hold (Output stabilization) Time Settings
<9. Calibration>
Calibration time
Hold (output stabilization)
time
IM 11M12A01-04E
9-7
F9.4E.ai
11th Edition : Jul. 19, 2017-00