Advertisement
Commercial Precision
Dilution Systems
Permeation Tube System
43iQ Instruction Manual
The exact SO
concentration is calculated from:
2
Where:
[SO
]
= diluted SO
2
OUT
[SO
]
= concentration of the undiluted SO
2
STD
F
= flow rate of the SO
SO2
= flow rate of the dilution air corrected to 25 °C and 760 mm Hg
F
D
Commercial precision dilution systems are available which reliably and
accurately dilute a high concentration gas mixture to provide a reliable span
gas. A high concentration (50 ppm) of SO
concentration range required.
The Thermo Scientific 146iQ Multi-gas Calibrator is one such system for
precision dilution.
Permeation tube systems which precisely maintain a set temperature to
within ±0.1 °C and hold a zero air flow rate to within ±0.5% can be used
for generation of span gas. The flow rate of the permeation system must be
at least 0.5 LPM for proper operation.
A permeation tube system, shown in
connections between components in the system should be made with glass,
PTFE, or other non-reactive material.
The air flow controllers should be capable of maintaining a constant air
flow within ±2% of the required flow rate. Ensure all devices are properly
calibrated and that all flows are corrected to 25 °C and 1 atm.
[
]
SO
2
[
=
STD
]
SO
2
OUT
+
F
D
concentration at the output manifold, ppm
2
standard corrected to 25 °C and 760 mm Hg
2
2
Figure 4–2
x
F
SO
2
F
SO
2
standard, ppm
2
in air is precisely diluted to the
can be constructed. All
Thermo Scientific
Advertisement
Chapters
