YOKOGAWA ZR202S, User Manual, Page: 125 / 163

<10. Other Functions>
10-18
IM 11M13A01-04E
10.5.2 Installing Gas Cylinders
Each ZO21S Standard Gas Unit comes with six zero gas cylinders including a spare. Each gas
cylinder contains 7-liters of gas with a 0.95 to 1.0 vol%O
2
(concentration varies with each cylinder) and
nitrogen, at a pressure of 700 kPaG (at 35°C).
The operating details and handling precautions are also printed on the product. Please read them
beforehand.
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.
For this operation, see Subsection 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 analyzer.
(2) Connect the tube connector port of the standard gas unit to the calibration gas inlet of the
analyzer, 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 analyzer.
(4) Enter the oxygen concentration of the sealed gas (noted from the cylinder) into the analyzer.
Also check that the oxygen concentration of the span gas is correctly set (21 vol%O
2
for clean
air). When using the ZO21S Standard Gas Unit (for use of the atmospheric air as a span gas),
use a hand-held oxygen analyzer to measure the actual oxygen concentration, and then enter it.