2.3 Equipment Requirements
2-9
AA-6800/6650 Instruction
When the GFA is used, provide gases with the specifications shown in Table 2.5.
Table 2.5 GFA Gas Specifications
Oxygen or air is effective in accelerating the ashing of organic samples. Prepare piping if necessary.
(2) Placement of gas cylinders
For safety, it is recommended that the cylinders be placed outdoors. Select a location for the cylinders
which satisfies the following conditions:
a. Not exposed to heat sources such as direct sunlight, furnaces, and heaters: Always keep the cylinders
at a temperature below 40 qC
b. Away from spark sources such as switchboards, ground wires, and high voltage power sources
c. Away from flammable materials such as oil, gasoline, and organic solvents
d. Sufficiently ventilated
e. If outdoors, not exposed to wind and rain
(3) Gas piping
If the cylinders are placed outdoors, piping must be performed separately within 5 m of the instrument. In
this case, be sure to follow the precautionary measures listed below.
a. Use stainless steel pipes for the piping. Do not use pipes that contain over 62 % copper for acetylene
piping.
b. Ensure that the pipe diameters are not too small to supply gas at the pressures indicated in
Table 2.4.
A pipe di
ameter of at least 7 mm will be sufficient.
c. Place a drain separator in the air piping system at the location indicated in
Figure 2.4. If a sufficiently
dry air supply source is
used, a drain separator is unnecessary.
d.
Figure 2.4 displays examples of recommended piping configurations.
e. Provide a hose nipple
with an outside diameter of 8.4 to 8.9 mm so that the provided gas supply hose
(inside diameter 7.9 mm) can be connected to the end of the gas piping.
CAUTION
If the gas supply pressure changes during the analysis, resultant changes in flame combustion will adversely
affect measurement reproducibility. Ensure that gas pressure does not fluctuate.
Supply pressure Max. consumption Purity
Argon 0.35 MPa 3.0 L/min t 99.9 %
Oxygen/Air 0.35 MPa 1.5 L/min Free from oil, moisture and dust
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