A sophisticated solution to the trials and tribulations of trace moisture analysis

Accurate and reliable trace moisture measurement in gases is critical in numerous industrial and scientific applications. Reliably calibrating trace moisture sensors is a considerable challenge because of the complexities of water vapour behavior and its interaction with materials. Conventional cylinder calibration methods often lack the requisite precision and stability, as they are static blends and lead to uncertainties in measurement. Water’s strong affinity for surfaces means that variations in temperature or pressure can lead to transient fluctuations, thereby making stabilization a lengthy process. Additionally, given the prevalence of water vapour in the environment, contamination of the gas standard during delivery to the analyser is an ongoing problem.

KIN-TEK Analytical’s Span Pac™ H₂O Trace Moisture Gas Standard Generator overcomes these challenges through an innovative differential method. Instead of relying on an absolute zero reference, which does not truly exist for trace moisture, this technique calibrates based on the change in analyzer response when a known water vapor concentration is introduced into a flowing diluent gas. This “standard addition” method effectively mitigates the influence of background gas variations and rectifies the unpredictability ubiquitous to traditional techniques.

The foundation of this system is the KIN-TEK Trace Source™ water permeation tube, which dynamically delivers a certified emission rate traceable to NIST through gravimetric weight loss over time. This guarantees a high level of precision, closely matching a primary standard even when a direct primary reference is unavailable. The flexibility of the Span Pac™ H₂O system enables concentration adjustments over a wide dynamic range, with instrument configurations that accommodate variations from 0.01 parts per million (ppm) to 10,000 ppm, depending on the model selected. The system can attain concentrations of less than 100 parts per billion (ppb) when using the welded model, demonstrating its suitability for highly sensitive applications.

For operation in industrial applications, the Span Pac™ H₂O system is built in a NEMA 4 cabinet with optional Z or X purge capabilities for enhanced safety. Using disposable and user-refillable permeation tubes further enhances its versatility and ease of use. With its robust design and ability to provide stable, traceable calibration gas standards, the Span Pac™ H₂O gas standard generator delivers a highly advanced, dependable option for trace moisture analysis. It offers a reliable solution for industries that demand the highest levels of precision and consistency in gas monitoring.