Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 127)

<10. Other Functions>
10-18
IM 11M12A01-04E
(2) Next, adjust the flow rate to 600 ± 60 ml/min using the span gas valve “AIR” (the flow check
ball stops floating on the green line when the valve is slowly opened). To rotate the valve
shaft, loosen the lock nut and turn it using a flat-blade screwdriver. Turning the valve shaft
counterclockwise increases the flow rate.
(3) After adjusting the flow rate, tighten the valve lock nut.
(4) After the measured oxygen concentration is stabilized, touch the [ENT] key, then all the digits
flash. Touch the [ENT] key again to display “ZEro Y”. Disconnect the power cord to stop the
pump.
<Flow of zero gas>
Touch the [ENT] key to display a zero gas value set with the parameter code B01. Touch the [ENT]
key again to flash “OPEn” and the “measured oxygen concentration” alternately. To cause the zero
gas flow, follow these steps:
(1) Use the needle of the zero gas valve “CHECK GAS” to puncture a hole in the gas cylinder
installed as described in Section 10.5.2. Fully clockwise turn the valve regulator by hand.
(2) Next, adjust the flow rate to 600 ± 60 ml/min (the flow check ball stops floating on the green
line when the valve is slowly opened). Turn the regulator of the zero gas valve back slowly
counterclockwise. At that time, the flow rate also decreases as the inner pressure of the gas
cylinder decreases. Monitor the flow check and, when the ball’s position changes greatly,
readjust the valve.
(3) Touch the [ENT] key after the measured oxygen concentration becomes stable. Then all the
digits flash. Touch the [ENT] key again so that the “CALEnd” flashes.
NOTE
Be sure not to terminate the 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 calibration
twice.
(4) Stop the zero gas flow. Turn the zero gas valve regulator fully clockwise. If this valve regulator
is not properly adjusted, the needle valve will not close completely and a cylinder gas may leak.
When the output stabilization time elapses, the calibration is complete.
<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.