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SEMI C54-1103 © SEMI 2003 6 10.2.2.4 Sample Flowrate: 500 cc/m inute or as specified by the instru ment manufacturer. 10.2.2.5 Wavelength: 4.75 m icrometers (4750 nm ) 10.2.2.6 Wavenumber: 2100 cm -1 10.2.3 Calibration S…

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SEMI C54-1103 © SEMI 2003 5
copper coils so that both the inlet stopper and the sided
outlet are in a downward position and shake gently for
1 to 2 minutes. Stand test bottle #3 on its base and
lower the leveling bottle so as to withdraw any residual
gases into the gas measuring burette (see Figure 2c).
Transfer at least 25 to 30 mL of test solution from the
left-hand leveling bottle #2 into the right-hand leveling
bottle #l, through the copper coil bottle #3, and the gas
burette while, at the same time, gently rocking and
tapping the center bottle (see Figure 2d). This will
move any bubbles that might cling to the copper coil
into the gas measuring burette.
9.5.4.4 Turn the stopcock off and raise the leveling
bottle #l so that its liquid level is the same as the liquid
level inside the upper portion of the gas burette (see
Figure 2e). When the levels of the leveling bottle and
the gas burette are the same, read the gas purity
markings on the burette at the liquid level at this point.
9.5.5 Maintenance
9.5.5.1 Copper coils should be added to the test bottle
as required to keep the bottles completely full. The gas
burette should be kept clean with a strong detergent
solution to eliminate drops of liquid that might hang up
in the gas space and give incorrect purity readings. No
readings should be taken when the space above the
liquid level of the gas burette has any liquid drops
hanging in it, as this will give an erroneous purity
reading.
9.5.5.2 The solution must be replaced occasionally as it
becomes exhausted. The necessity of replacement may
be determined when the color begins to turn green, and
by the increased length of shaking time required to get a
minimum acceptable purity from the oxygen in a
cylinder of known purity. Suspect an exhausted solution
if analysis of a cylinder of known purity does not read
the correct purity.
9.5.6 Standardization
9.5.6.1 The method of analysis stated above can be
used as a primary standard, meaning cylinders analyzed
by this method can be used as standards of
measurement on electronic analyzers used to measure
oxygen.
9.5.6.2 This method is specific to oxygen when carbon
dioxide is not present in the sample gas. When carbon
dioxide is one of the components of the sample gas, the
carbon dioxide must first be scrubbed from the sample.
10 Analytical Procedures for Grade 3.8
Oxygen (See Notes 1 in 9.2.4.1 and 9)
NOTE 9: All gases used in the analysis of the sample should
contain not more than 10% of the sample value of the
component of interest unless otherwise specified
10.1 Argon — This procedure is for the determination
of argon using a gas chromatograph with a thermal
conductivity detector.
10.1.1 Detection Limit — 25 ppm.
10.1.2 Instrument Parameters
10.1.2.1 Column: 3.6 m (12 ft) by 3.2 mm (1/8 in)
stainless steel tubing packed with molecular sieve 5A,
60/80 mesh, washed to remove fines and activated at
300°C for 24 hours or equivalent.
10.1.2.2 Carrier Flow: 45 mL/min helium.
10.1.2.3 Sample Volume: 1–3 mL.
10.1.2.4 Temperatures:
Detector 40°C
Column −50°C
10.1.3 Calibration Standard — 50–150 ppm argon,
balance helium.
10.1.4 Operating Procedure (Refer to Figure 3.)
10.1.4.1 With the valve in Position A, purge the sample
loop with the calibration standard. Switch the valve to
Position B to inject the sample into the column. After
the argon has been detected, switch the valve back to
Position A to backflush the oxygen from the column.
Record the peak area and retention time.
10.1.4.2 Inject oxygen sample to be tested in the same
manner as in Section 10.1.4.1. Record the retention
times and peak areas.
10.1.4.3 Repeat Section 10.1.4.2.
10.1.4.4 Calculate the concentration of argon in the
sample, using the formula below. The result may not
exceed the specification Section 7 of this standard.
Sample of
ionConcentrat
Standard of
ionConcentrat
AreaPeak Standard
AreaPeak Sample
=×
10.2 Carbon Monoxide — This procedure is for the
determination of carbon monoxide using dual beam
optical non-dispersive infrared spectrophotometry.
10.2.1 Detection Limit — 0.2 ppm.
10.2.2 Instrument Parameters
10.2.2.1 Detector: “Luft” type or equivalent
10.2.2.2 10" Infrared Gas Cell or gas cell with
equivalent sensitivity
10.2.2.3 Sample Cell Pressure: 200 psig for full scale
range 0–20 ppm carbon monoxide or appropriate
pressure recommended by the cell manufacturer.
SEMI C54-1103 © SEMI 2003 6
10.2.2.4 Sample Flowrate: 500 cc/minute or as
specified by the instrument manufacturer.
10.2.2.5 Wavelength: 4.75 micrometers (4750 nm)
10.2.2.6 Wavenumber: 2100 cm
-1
10.2.3 Calibration Standard — 5 ppm carbon
monoxide, balance oxygen.
10.2.4 Operating Procedure (See Notes 10, 11) (Refer
to Figure 4).
NOTE 10: An example of an operating procedure is outlined
below for the sample system shown in Figure 3. This
procedure is appropriate only when the infrared gas cell is
designed to withstand the 200 psig sample pressure.
NOTE 11: Operating procedures for other non-dispersive
infrared analyzers vary depending on manufacturer. Refer to
individual instrument vendor instructions in each case.
10.2.4.1 Open the zero gas (pre-purified nitrogen or
certified pure oxygen, independently measured to be
less than 0.1 ppm CO) cylinder valve. Open valve V1,
close valves V2 and V3. Flow the gas through the
system and adjust the back pressure regulator to 200
psig as shown on gauge G. Adjust the flowrate on the
flowmeter to 1000 cc/minute by adjusting valve V1.
After a constant readout is observed, adjust the zero
control knob of the analyzer to set the absorbance
output to read zero.
10.2.4.2 Open the calibration gas standard cylinder
valve. Close V1 and V2, and open valve V3. Flow the
calibration gas through the system and adjust the back
pressure regulator to 200 psig. Adjust the flowrate on
the flowmeter to 1000 cc/minute. After a constant
readout is observed, record the absorbance of the
calibration standard, if the instrument indicates
absorbance directly. If the instrument indicates
concentration, adjust the span control to read the
concentration of carbon monoxide in the calibration
gas.
10.2.4.3 Introduce the oxygen sample into the analyzer
by closing valves Vl and V3, opening valve V4 and
slowly opening valve V2 until the flowrate on the
flowmeter is 1000 cc/minute. Adjust the back pressure
regulator to 200 psig. If the instrument indicates
absorbance, read the absorbance of the sample and
calculate the quantity of carbon monoxide, using the
formula below. If the instrument indicates
concentration, record the concentration. The results
may not exceed the specification in Section 7 of this
standard.
Sample of
ionConcentrat
Standard of
ionConcentrat
Standard of Absorbance Measured
Sample of Absorbance Measured
=×
10.3 Carbon Dioxide — This procedure is for the
determination of carbon dioxide using dual beam
optical non-dispersive infrared spectrophotometry.
10.3.1 Detection Limit — 0.05 ppm.
10.3.2 Instrument Parameters
10.3.2.1 Detector: “Luft” type or equivalent
10.3.2.2 10" Infrared Gas Cell or gas cell with
equivalent sensitivity
10.3.2.3 Sample Cell Pressure — 100 psig for full
scale range 0–5 ppm carbon dioxide; 200 psig for full
scale range of 0–2.5 ppm carbon dioxide or appropriate
pressure as recommended by cell manufacturer.
10.3.2.4 Sample Flowrate: 500 cc/minute or as
specified by the instrument manufacturer
10.3.2.5 Wavelength: 4.4 micrometers (4400 nm)
10.3.2.6 Wavenumber: 2250 cm
-1
10.3.3 Calibration Standard — 5 ppm carbon dioxide,
balance oxygen.
10.3.4 Operating Procedure — (See Notes 10, 11 in
10.2.4.) (Refer to Figure 4.)
10.3.4.1 Open the zero gas (prepurified nitrogen or
pure oxygen, independently measured to be less than
0.1 ppm CO
2
) cylinder valve. Open valve V1, close
valves V2 and V3. Flow the gas through the system and
adjust the back pressure regulator to 100 psig as shown
on gauge G. Adjust the flowrate on the flowmeter to
1000 cc/minute by adjusting valve Vl. After a constant
readout is observed, adjust the zero control knob of the
analyzer to set the absorbance output to read zero.
10.3.4.2 Open the calibration gas standard cylinder
valve. Close V1 and V2, and open valve V3. Flow the
calibration gas through the system and adjust the back
pressure regulator to 100 psig. Adjust the flowrate on
the flowmeter to 1000 cc/minute. After a constant
readout is observed, record the absorbance of the
calibration standard, if the instrument indicates
absorbance directly. If the instrument indicates
concentration, adjust the span control to read the
concentration of carbon dioxide in the calibration gas.
10.3.4.3 Introduce the oxygen sample into the analyzer
by closing valves V1 and V3, opening valve V4 and
slowly opening valve V2 until the flowrate on the
flowmeter is 1000 cc/minute. Adjust the back pressure
regulator to 100 psig. If the instrument indicates
absorbance, read the absorbance of the sample and
calculate the quantity of carbon dioxide, using the
formula below. If the instrument indicates
concentration, record the concentration. The results
SEMI C54-1103 © SEMI 2003 7
may not exceed the specification in Section 7 of this
standard.
Sample of
ionConcentrat
Standard of
ionConcentrat
Standard of Absorbance Measured
Sample of Absorbance Measured
=×
10.4 Krypton and Nitrogen — This procedure is for the
determination of krypton and nitrogen using a gas
chromatograph with a thermal conductivity detector.
10.4.1 Detection Limits — 3 ppm krypton, 3 ppm
nitrogen.
10.4.2 Instrument Parameter
10.4.2.1 Column: 3.6 m (12 ft) by 3.2 mm (1/8 in)
stainless steel tubing packed with molecular sieve 5A,
60/80 mesh, washed to remove fines and activated at
300°C for 24 hours or equivalent.
10.4.2.2 Carrier Flow: 45 mL/min helium.
10.4.2.3 Sample Volume: 25 mL.
10.4.2.4 Temperatures:
Detector 40°C
Column 25°C
10.4.3 Calibration Standards — 5–15 ppm krypton, 5–
15 ppm nitrogen, balance helium.
10.4.4 Operating Procedure (Refer to Figure 5)
10.4.4.1 With the valve in Position A, purge the sample
loop with the calibration standard. Switch the valve to
Position B to inject the sample into the column and
allow the oxygen to pass through the column to vent.
Switch valve to Position A to allow the krypton and
nitrogen to be carried to the detector. Record the peak
areas and retention times.
10.4.4.2 Inject the sample to be tested in the same
manner as Section 10.4.4.1. Record the retention times
and peak areas.
10.4.4.3 Repeat 10.4.4.2.
10.4.4.4 Calculate the concentrations of krypton and
nitrogen using the formula below. The result may not
exceed the specification in Section 7 of this standard.
Sample of
ionConcentrat
Standard of
ionConcentrat
AreaPeak Standard
AreaPeak Sample
=×
10.5 Nitrous Oxide — This procedure is for the
determination of nitrous oxide using dual beam optical
non-dispersive infrared spectrophotometry.
10.5.1 Detection Limit — 0.05 ppm.
10.5.2 Instrument Parameters
10.5.2.1 Detector: “Luft” type or equivalent
10.5.2.2 10" Infrared Gas Cell or gas cell with
equivalent sensitivity
10.5.2.3 Sample Cell Pressure: 200 psig for full scale
range 0–5 ppm nitrous oxide or appropriate pressure as
recommended by the cell manufacturer.
10.5.2.4 Sample Flowrate: 500 cc/minute or as
recommended by the instrument manufacturer
10.5.2.5 Wavelength: 4.5 micrometers (4500 nm)
10.5.2.6 Wavenumber: 2222 cm
-1
10.5.3 Calibration Standard: 5 ppm nitrous oxide,
balance oxygen.
10.5.4 Operating Procedure — (See Notes 10, 11 in
Section 10.2.4.) (Refer to Figure 4.)
10.5.4.1 Open the zero gas (prepurified nitrogen or
certified pure oxygen, independently measured to be
less than 0.1 ppm N
2
O) cylinder valve. Open valve V1,
close valves V2 and V3. Flow the gas through the
system and adjust the back pressure regulator to 200
psig as shown on gauge G. Adjust the flowrate on the
flowmeter to 1000 cc/minute by adjusting valve Vl.
After a constant readout is observed, adjust the zero
control knob of the analyzer to set the absorbance
output to read zero.
10.5.4.2 Open the calibration gas standard cylinder
valve. Close Vl and V2, and open valve V3. Flow the
calibration gas through the system and adjust the back
pressure regulator to 200 psig. Adjust the flowrate on
the flowmeter to 1000 cc/minute. After a constant
readout is observed, record the absorbance of the
calibration standard, if the instrument indicates
absorbance directly. If the instrument indicates
concentration, adjust the span control to read the
concentration of nitrous oxide in the calibration gas.
10.5.4.3 Introduce the oxygen sample into the analyzer
by closing valves Vl and V3, opening Valve V4 and
slowly opening valve V2 until the flowrate on the
flowmeter is 1000 cc/minute. Adjust the back pressure
regulator to 200 psig. Read the absorbance of the
sample and calculate the quantity of nitrous oxide,
using the formula below. If the instrument indicates
concentration, record the concentration. The result may
not exceed the specification in Section 7 of this
standard.
Sample of
ionConcentrat
Standard of
ionConcentrat
Standard of Absorbance Measured
Sample of Absorbance Measured
=×