Calibration Gas Flow - YOKOGAWA ZR402G User Manual

To install the gas cylinder, follow these steps:
(1) Attach the zero gas valves onto the gas cylinder. First, turn the valve regulator of the zero
gas valves counterclockwise to completely retract the needle at the top from the gasket
surface. Maintaining the valve in this position, screw the valve mounting into the mouthpiece
of the gas cylinder. (If screw connection is proper, you can turn the screw manually. Do not
use any tool.) When the gasket comes in contact with the mouthpiece of the gas cylinder
and you can no longer turn it manually, tighten the lock nut with a wrench.
(2) Remove the carrying case from the standard gas unit. The case is attached to the unit with
six screws. So, loosen the screws and lift them off.
(3) Slide the gas cylinder through the hole in the back of the unit and connect the tube (the
piping in the unit) to the valve connections. Insert each tube at least 10 mm to prevent
leakage, and secure it using a tube clamp.
(4) Attach the gas cylinder to the case. Extend the valve regulator of the zero gas valves
through the hole in the front panel of the unit and secure the bottom of the cylinder with the
clamp.
(5) Take note of the oxygen concentration of the sealed gas indicated on the gas cylinder
and replace the carrying case. Enter the oxygen concentration of the sealed gas using
the parameter code B01 as a zero gas oxygen concentration. Also check that no piping is
disconnected.
Thus, the work of installing a gas cylinder is completed. However, gases in the cylinders cannot
immediately flow out after these procedures. To discharge the gases, it is necessary for the
needle in the zero gas valves to puncture a hole in the gas cylinder (see Section 10.5.3).
10.5.3

Calibration Gas Flow

<Preparation before calibration>
(1) To operate the standard gas unit, place it on a nearly horizontal surface in order to allow the
flow check to indicate the precise flow rate. In addition, a power supply for driving the span
gas (air) supply pump is required near the unit (the length of the power cord attached to the
unit is 2 m). Select a suitable location for the unit near the installation site of the converter.
(2) Connect the tube connector port of the standard gas unit to the calibration gas inlet of the
detector, using a polyethylene resin tube with an outside diameter of 6 mm. Be careful to
prevent gas leakage.
(3) Fully open the stop valve mounted on the calibration gas inlet of the detector.
(4) Enter the oxygen concentration of the sealed gas (noted from the cylinder) into the
converter. Also check that the oxygen concentration of the span gas is correctly set (21 vol%
O for clean air). When using the ZO21S Standard Gas Unit (for use of the atmospheric
2
air as a span gas), use a hand-held oxygen analyzer to measure the actual oxygen
concentration, and then enter it.
<Flow of span gas (air)>
The standard gas unit is used only when manual calibration is employed.
Therefore, the timing for flowing span gas (air) is included in the manual calibration flowchart
described in Section 7.11.2, earlier in this manual. For operation of the converter, see Section
7.11.2.
(1) When the "OPEn" and the "measured oxygen concentration" are alternately displayed
during calibration, plug the power cord into the power supply socket to start the pump of the
standard gas unit.
(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.
<10. Other Functions>
IM 11M12A01-04E 11th Edition : Jul. 19, 2017-00
10-22