Development of humidity standard in trace-moisture region: Characteristics of humidity generation of diffusion tube humidity generator

Uncertainty Analysis of Evaporation Rate in Magnetic Suspension Balance/Diffusion-Tube Humidity Generator

“…This dry gas was introduced into the inlet of a generation chamber and a bypass line using two thermal mass flow controllers (Stec, SEC-F440M). The total flow rate was maintained at 2.5 L · min −1 or 20 L · min −1 , and the flow rate to the chamber was 0.1 L · min −1 ; the flow rates in L · min −1 used in this paper correspond to those measured under the standard conditions of 101.325 kPa and 0 • C. Inside the chamber, a diffusion cell [11] was suspended from the measuring load of an MSB (Rubotherm). Water was stored in the diffusion cell, and water vapor that evaporated through the diffusion tube was diluted with dry N 2 gas coming from the inlet.…”

Extremely Fast 1 μmol · mol−1 Water-Vapor Measurement by a 1 mm Diameter Spherical SAW Device

“…5. In this system, water-vapor concentration of the wet gas line n w can be determined by dimensions of a diffusion tube (length L and cross-section area S) and water-vapor concentration of water vessel e shown as follows [9]:…”

A fiber optic sensor with a metal organic framework as a sensing material for trace levels of water in industrial gases

“…The required levels of trace water in purified gases have decreased with integration and downsizing in semiconductor productions. In 2007, the National Metrology Institute of Japan established a certified reference material for trace moisture in nitrogen using a permeation tube method [17]. Since 2009, this method has been used to provide traceability to National Institute of Standards and Technology (NIST) for trace water at levels from 12 to 1200 nmol mol -1 .…”