Teledyne 6200T - Sulfides Analyzer User Manual
Page 64
Getting Started
Model 6200T Total Sulfur Analyzer
Teledyne Analytical Instruments
64
One primary application of this instrument is to analyze CO
2
sample gas for sulfur
containing impurities. Typically the impurities should be at low levels; therefore it is
especially important that the zero calibration of the analyzer is done accurately so that
even small levels of impurities can be detected.
CO
2
Source
For this type of application, a source of CO
2
that is free of sulfides is required for
accurate zero calibration of the instrument. If the ‘zero gas’ used to zero the instrument
is contaminated, the process gas will read artificially low, sometimes even showing a
negative TS concentration. Standard CO
2
bottles can have unacceptably high levels of
sulfur compounds in them. Beverage grade CO
2
should be used as a diluent as well as
the ‘zero gas’ source for calibration of the 6200T.
Since CO
2
strongly quenches the SO
2
fluorescence reaction, the instrument sensitivity
will be greatly reduced when using CO
2
as the balance gas. Therefore it is imperative
that the 6200T be calibrated using CO
2
as the balance gas when it will be measuring TS
in a gas matrix that is primarily CO
2
.
CO
2
liquefies when compressed, and sulfur compounds do not stay dissolved in liquid
CO
2
. Therefore it is not practical to use compressed gas bottles of H
2
S in CO
2
for
calibration purposes. TAI strongly recommends that H
2
S in N
2
bottles be used for
calibration of the 6200T, and that a calibrator be used to mix zero gas (CO
2
) into the cal
gas stream, making the final calibration gas mostly CO
2
.
3.3.2.1. Basic Connections Including w/Span Gas and w/Gas Dilution
Calibrator
Refer to Figure 3-4 and Table 3-3 while making the pneumatic connections as follows:
SAMPLE inlet
Connect ¼” gas line not more than 2 m long, from sample gas
source to this inlet.
When no zero/span/shutoff valve options, also connect line from
calibration gas source to this inlet, but only when a calibration
operation is actually being performed.
EXHAUST outlet
Connect exhaust line made of PTEF tubing; minimum O.D ¼”, to
this fitting. The exhaust line should be no longer than 10 meters,
and should lead outside the shelter or immediate area surrounding
the instrument.
Figure 3-16 and Figure 3-17 illustrate pneumatic connections for two of the possible
basic configurations.