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Appendix
recommended because they tend to cause excessive internal expansion
which may result in seal failure.
For operation at cell pressures other than atmospheric, care must be
taken not to change the sample pressure rapidly or cell damage may
occur. For cell pressures above atmospheric, caution must be exercised
to avoid over pressuring the cell holder. (Percent analyzers will require
some type of cell retainer to prevent the cell from being pushed out by
the pressure). For operation at pressures below atmospheric pressure a
suffix C (clamped) cell is required.
RESTRICTION DEVICES:
For proper operation, all 3000 series analyzers require a flow
restriction device. This device is typically a restrictor or a valve. This
restriction device serves two functions in the sample path. The first
function is to limit the flow rate of the sample through the analyzer. A
restrictor is chosen to operate over a range of pressures and provide a
useable flow rate over that range.
The second function that the restriction device provides is a
pressure drop. This device is selected to provide the only significant
pressure drop in the sample path.
RESTRICTOR KIT
The current revision of the 3000RS series analyzers are supplied
with a restrictor and a union which are user installed. These parts
supplied to give the end user more flexibility when installing the
analyzer. A restrictor is available for high or low positive pressure
applications as well as vacuum service (atmospheric pressure sample)
applications (see manual for installation instructions).
The standard high-pressure restrictor is recommended for pressures
between 5 psig and 50 psig. For positive low-pressure application (5
psig or less) the low-pressure restrictor is better suited. For non-
pressurized sample applications, the marked restrictor should be used
and configured for vacuum service.
For extremely low positive pressure applications (less than 2 psig)
the vacuum service configuration should provide higher performance
(higher flow rates). For vacuum service the end user must supply a
vacuum pump and a bypass valve for the pump. A vacuum level of 5 -
10 inches of mercury should provide the optimum flow rate.
Teledyne Analytical Instruments
3000RS-P
118
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