Welded Models Available for Trace Moisture Below 100 ppb
Single Oven(Span Pac™ 61-W-H2O)
Single Oven with Secondary Dilution (Span Pac™ 61-W-H2O-SD)
The welded (W) instrument is required for applications that generate one or more moisture concentrations below 100 ppb. (Welded models can also be used for higher moisture concentrations.)
In single-oven models with only primary dilution (i.e., no secondary dilution), the minimum moisture concentration of 5 ppb is set by the minimum practical permeation tube emission rate and maximum allowed dilution flow rate. The secondary dilution model can generate moisture concentrations much lower.
The welded model has the same features and functions as the non-welded model including purge port and heated electro-polished stainless steel tubing. In addition, the tubing is seamless with orbitally-welded joints to further reduce the possibility of outboard-to-inboard atmospheric moisture contamination. The addition of special hardware components insures high-purity service.
All non-welded models are also available in NEMA 4 enclosures for use in industrial environments. Optional capabilities include (1) Z-purge for Class 1, Group C or D, Division II and (2) X -purge for Class 1, Group C or D, Division I.