KIN-TEK’s Span Pac™ H2O – SD (second dilution) uses a Trace Source™ permeation tube to add a precisely known, adjustable, trace concentration of water vapor into a flow of dry matrix gas to create calibration standards for trace moisture monitors. Then, a second dilution stage takes an adjustable aliquot of that primary mixture and further dilutes it with matrix gas to create substantially lower concentrations. According to the company:
- This two-stage dilution method allows the output concentration of trace moisture to be varied seamlessly over a range of up to 10,000:1 from a single permeation tube.
- The system is designed to add water vapor concentrations in the range from 100ppb to over 5,000ppm.
- An alternate function of the two-stage dilution system is to generate a variable moisture concentration while maintaining constant total flow; in this mode, the concentration can still be varied over a range of up to 400:1.
- The Standard Additions Technique is used to compensate for residual moisture in the matrix gas — in use, accuracy of the measuring device is achieved by calibration on the differential response due to the moisture addition.
- The moisture concentration added by the Span Pac™ H2O - SD is traceable to NIST through physical standards.