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Appendix C Scan/Calibration Procedure
F.
CALIBRATION
1. Calculate five injection volumes that cover the complete concentration range
(also see Chapter 12). E.g., if the concentration is 0 to 1000 ppm, the
concentrations should be approximately 200, 400, 600, 800, and 1000 ppm.
For liquid injection volumes
For gas injection volumes
Where:
VI = injection volume in microliters (L)
C = concentration volume in parts per million (ppm)'
V
= total volume of cell and calibration system in liters (2.24L)
T
d =
Liquid density (g/cm
M =
Molecular weight of sample
P
Molar volu
R
Note : In the above example, 200 (the lowest concentration ) x 2.24 (the cell
volume) = an injection volume of 448 L. Since most syringes are not precise
enough to measure an injection volume of 448 L, select an injection volume
that can be accurately measured by the syringe. In the above example it will
be 450 L. Transpose the formula to C = V
concentration (C). In this example, C = 450/2.24 = 200.1. Record both the
concentrations and injection volumes.
2. From the Main Menu select "1=Analyze/Start"
3. Select "1=New Zero"
4. At the prompt "Install chemical filter", attach the Closed Loop Calibration
System and turn the pump on. Select "Enter=Continue"
5. Allow instrument to purge with "Zero Air" or clean air.. The instrument will
purge for 1 minute then proceed to set the Zero.
6. At the prompt for "Install Particulate filter", keep the Closed Loop Calibration
System attached. Press "Enter=Continue" and allow the instrument to purge
the Zero Air sample. When the purge is complete, select or until the
Absorbance screen appears. Verify that the absorbance equals zero(+/- .0010).
3
Depending upon the compound, either a gas or liquid may be injected,. Many compounds (e.g., benzene)
are not readily available in gaseous form, and are therefore inserted into the pump as a liquid. The pump
evaporates the liquid before it is introduced to the analyzer.
3
, use the formula:
3
, use the formula: VI = (C) (V
3
)
1
me
of
gas
at
25
24.4
C-10
V
T
VI
C
3
10
).
T
C
/V
, and solve for the
i
T
P
M
R
d
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