Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 80)

<7. Startup>
7-15
IM 11M12A01-04E
7.10 Calibration
The converter is calibrated in such a way that the actual zero and span gases are measured and
those measured values are used to agree with the oxygen concentrations in the respective gases.
There are three types of calibration procedures available:
(1) Manual calibration conducting zero and span calibrations, or either of these calibrations in turn.
(2) Semi-automatic calibration which uses the infrared switches or a contact input signal and
conducts calibration operations based on a preset calibration time and stable time.
(3) Automatic calibration conducted at preset intervals.
Manual calibration needs the ZA8F Flow Setting Unit to allow manual supply of the calibration gases.
Semi-automatic and automatic calibrations need ZR20H Automatic Calibration Unit to allow automatic
supply of the calibration gases. The following sections set forth the manual calibration procedures.
For details on semi-automatic and automatic calibrations, consult Chapter 9, “Calibration,” later in this
manual
7.10.1 Calibration Setup
Set the following three items before carrying out a calibration. Parameter codes for these set items are
listed in Table 7.11.
(1) Mode setting
There are three calibration modes: manual, semi-automatic, and automatic.
Select the desired mode. This section uses manual mode for calibration.
(2) Oxygen concentration in zero gas
Enter the zero gas oxygen concentration for calibration.
(3) Oxygen concentration in span gas
Enter the span gas oxygen concentration for calibration. If instrument air is used, enter 21 vol %
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
If instrument air is used for the span gas, dehumidify the air to a dew point of -20°C and remove any
oil mist or dust.
Incomplete dehumidifying or unclean air will have an adverse effect on the measurement accuracy.
Table 7.11 Calibration Parameter Codes
Set item Parameter code Set value
Calibration mode B03 0 Manual calibration
1 Semi-automatic calibration
2 Automatic calibration
Zero gas oxygen concentration B01 Enter oxygen concentration.
Span gas oxygen concentration B02 Enter oxygen concentration.