Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 93)

IM 11M12A01-05E 7-20
7.10 Calibration
The converter is calibrated in such a way that the actual zero and span gases are mea-
sured 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 calibra-
tions 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 the 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 7.12.
(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 atmo-
spheric 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 -208 C and
remove any oil mist or dust.
Incomplete dehumidifying or unclean air will have an adverse effect on the measurement
accuracy.
Table 7.12 Calibration Parameter Codes
T7.12E.EPS
Set item Parameter code Set value
B03
B01
B02
Mode
Zero-gas oxygen
concentration
Span-gas oxygen
concentration
0: Manual calibration
1: Semi-automatic calibration
2: Automatic calibration
Enter oxygen concentration.
Enter oxygen concentration.