Methods Of Operating Valves In The Za8F Flow Setting Unit; Preparation Before Calibration; Operating The Span Gas Flow Setting Valve - YOKOGAWA ZR22G User Manual

NOTE
Be sure not to terminate a calibration in progress because of a shortage of gas in the cylinder.
Each gas cylinder is operable for nine minutes or more provided the gas is discharged at the
specified rate. Therefore, if your calibration time is estimated at four minutes, you can operate the
zero-point calibration twice.
<Treatment after completion of calibration>
(1) Fully close the stop valve mounted on the calibration gas inlet of the detector.
(2) Remove the tube connecting the detector to the standard gas unit.
WARNING
Store the standard gas unit with the gas cylinder mounted where the ambient temperature does
not exceed 40°C. Otherwise, the gas cylinder may explode. Store the spare gas cylinders under
the same condition.
10.12 Methods of Operating Valves in the ZA8F
Flow Setting Unit
The ZA8F Flow Setting Unit is used as a calibration device for a system conforming to System
2. Calibration in such a system is to be manually operated. So, you have to operate the valve of
the Flow Setting each time calibration is made (starting and stopping the calibration gas flow and
adjusting the flow rate). This applies even if you are using the ZR40H Automatic Calibration Unit.
For operation of the converter, see Section "7.12
10.12.1

Preparation Before Calibration

To operate the ZA8F Flow Setting Unit, prepare for calibration as follows:
(1) Check for a complete closing of the zero gas flow setting valve in the unit and open the
regulator valve for the zero gas cylinder until the secondary pressure equals sample gas
pressure plus approx. 50 kPa (or sample gas pressure plus approx. 150 kPa when a check
valve is used, maximum pressure rating is 300 kPa).
(2) Check that the oxygen concentration of the zero gas and span gas (instrument air 21
vol%O ) in the cylinder is set in the converter.
2
10.12.2

Operating the Span Gas Flow Setting Valve

The following description is given assuming that instrument air, the same as the reference gas, is
used as the span gas.
(1) When the display shown in Figure 10.15 appears during calibration, open the span gas
flow setting valve of the flow setting unit and adjust the flow rate to 600 ± 60 ml/min. Turn
the valve slowly counterclockwise after loosening the lock nut if the valve has a lock nut. To
check the flow rate, use the calibration flowmeter. If the sample gas pressure is extremely
high, adjust the sample gas pressure to obtain pressures (listed in Table 10.7) ± 10%.
Table 10.11
Sample gas pressure (kPa)
Flow rate (ml/min)
Calibration", earlier in this manual.
50 100 150
500 430 380
<10. Other Functions>
200 250
350 320
IM 11M12G01-02EN 1sh Edition : Mar. 25, 2021-00
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