Description
The Span Pac™ H2O instrument works on a differential principal. Application of this principle is meaningful when the moisture content of the background diluent gas exceeds 10 percent of the minimum concentration to be generated. Calibration is based on the change in analyzer response caused by the addition of a known water vapor concentration from a KIN-TEK Trace Source™ water permeation tube to a flowing stream of the diluent gas. This differential method overcomes the “no zero” problem, and the problem of the background gas affecting the response.
The permeation tube emission rate is certified by the Factory traceable to NIST by gravimetric weight loss over time. This provides a close approximation to a primary standard, even in situations where primary standards are not available.
KIN-TEK takes special care in design, construction and choice of hardware components to minimize errors due to atmospheric contamination and interactions with other materials in the system.