Yokogawa AC8 Calibration Units - Manual (Page 10)

10
IM 11M6D2-02E-A
Figure 7.1 Calibration Mode Setting
7.1.2 Calibration Setup Procedure
Either Span or Zero or both calibrations can be performed.
Normally select both: Span-Zero.
<Setting Procedure>
From [Maintenance]‡ [Calibration setup] display, select
[Points], then a selection window opens and Span-Zero,
Span or Zero may be selected. Figure 7.2
Figure 7.2 Procedures for Setting Calibration Mode.
7.1.3 Zero Gas Concentration
This sets the oxygen concentration of the zero gas used for
calibration. Enter the value from the label of the correspond-
ing gas bottle.
7.1.4 Span Gas Concentration
This sets the oxygen concentration of the span gas used for
calibration. When the instrument air supply is used as the
span gas, enter 21% O2.
NOTE
When the instrument air supply is to be used as a span gas, cool
the gas to -20ºC below the dew point to remove moisture, oil
mist and dust from the air. If this air purification is not per-
formed, the accuracy of the calibration may be affected.
<Setting Procedure>
1) From the [Calibration setup] display, select [Zero gas
conc.], and the numerical data entry is display is displayed.
Enter the oxygen concentration of the zero gas used for cali-
bration. For example, enter 0.98 vol% O2 as [00098].
2) From the [Calibration setup] display, select [Span gas
conc.], and the numerical data entry is display is displayed.
Enter the oxygen concentration of the span gas used for
calibration. For example, enter 21 vol% O2 as [02100].
3) Calibration time setting
If the mode is [Man]:
Select [Hold time]. This is the output stabilization (settling)
time required from calibration end until measurement is
reentered. During this time, the calibration gas is switched to
measurement gas and the measurement gas is allowed time
to stabilize. Setting range is from 00 min. to 60 min 59 sec.
The analog outputs of individual channels which are under
calibration remain Output Hold status from the start of cali-
bration until the end of the stabilization (settling) time, and
their output is not included in the averaging group calcula-
tions during this time.
If the mode is in [Semi-Auto]:
In addition to the above [Hold] output stabilization (settling)
time, there is also a [Cal. Time] setting. This is the setting
time from when calibration gas flow is started until calibra-
tion is performed. The same time setting is used for both
Zero and Span calibration. Setting range is from 00 min. to
60 min 59sec. Calibration time and stabilization time, and
analog output status are shown on the calibration timing
chart of Figure 7.3 below. For solenoid valve (SV) piping and
wiring refer to Section 5 of AV550G manual.