Instruction manual

10.0 OTHER FUNCTIONS SM425 INSTRUCTION MANUAL

42500001 REV A 169

To install the gas cylinder, follow these steps:

1. Install the zero gas valves onto the gas cylinder. Before installing, turn the valve regulator of the

zero-gas valve counterclockwise to completely retract the needle away at the top from the gasket

surface. With the valve in this position, manually screw the valve mounting into the mouthpiece of

the gas cylinder. Use a wrench to make final tightening adjustment.

2. Remove the carrying case from the standard gas unit. The case is attached to the unit with six

screws.

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 as indicated on the gas cylinder.

Replace the carrying case. Enter the oxygen concentration of the sealed gas into the analyzer

using the instructions on the converter display. Also check that no piping is disconnected.

Follow the instructions in section 1.57.3 to flow gas from the Standard Gas Unit.

10.5.3 Calibration Gas Flow

1. To operate the standard gas unit, place it on a horizontal surface to allow the flow check to

indicate an accurate flow rate. The unit requires ac power for driving the span gas (air) supply

pump (the length of the power cord attached to the unit is 2 m).

2. Connect the tube connector port of the standard gas unit to the calibration gas inlet of the

detector. Use a polyethylene resin tube with an outside diameter of 6 mm. Be careful to prevent

gas leakage.

3. Fully open the needle 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 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 air as a span gas), use a

hand-held oxygen analyzer to measure the actual oxygen concentration.

The standard gas unit is used only when manual calibration is employed. The timing for flowing span gas

(air) is included in the manual calibration flowchart described in Section 1.57.2. For operation of the

converter, see Section 1.44.

1. When the message “Open span gas valve” is displayed on the converter display during

calibration, plug the power cord into the ac socket to start the pump of the standard gas unit.