Teledyne 2120XL - Trace Nitrogen Analyzer - Manual (Page 42)

Installation Model 2120XL
Teledyne Analytical Instruments 30
The sample manifold system must be designed so that you can:
 Purge the sample line and pre-adjust the flow rate before
admitting a sample to the analytical cell.
 Maintain a flow of argon through the analytical cell
whenever ionization voltage is being applied.
The following guidelines are presented as an aid in constructing a
suitable external sampling system for the Model 2120XL:
 Alter the geometry of the system in Figure 3-2, as necessary,
to suit your specific needs and to maintain access to items on
the rear panel. However, alterations should be adhered to
schematically.
 Use 1/8-inch (0.32 cm) electro-polished stainless steel tubing
for all parts of the manifold between the source and sample
inlet connections of the analyzer. Although you can use 1/4-
inch (0.64 cm) tubing, it is not recommended. The manifold
should be a welded assembly wherever possible.
 Use only high-purity components with metal seals.
 Eliminate excess components.
 Minimize "dead spaces" in the sample lines.
 Use a 1/8 inch compression fitting for the analyzer inlet
connection.
 Use a high-quality regulator or device to maintain a constant
pressure to the zero, sample, and span inlet lines. Teledyne
recommends using a high-purity regulator with the following
specifications:
 2-stage tiered diaphragm
 100 psi outlet
 15 RA max
 5 ports
 CGA 580 welded on inlet side
 1/8 M (1 port), 1/8 F (1 port)
 2 gauges