A novel dynamic method for the storage of calibration gas mixtures based on thermal mass flow controllers

Abstract

A dynamic method for the storage of calibration gas mixtures is presented using thermal mass flow controllers (MFCs) connected to a dead end volume. The approach relies on barometry to calibrate the unknown constant volume and two MFCs which regulate the flow rate of carbon dioxide and methane respectively. Binary gas mixtures of these components are prepared and stored within the calibrated volume tank up to 9 bar at ambient temperature. Thermodynamic data of pressure, temperature and density of the gas mixtures are retrieved. The expanded uncertainties at 95% confidence level of the molar fraction and the density of the mixture are evaluated. FTIR Spectroscopy is used in situ to analyze the gas mixtures.

Sorption of CO2, CH4 and Their Mixtures in Amorphous Poly(2,6-dimethyl-1,4-phenylene)oxide (PPO)

“…Mixed gas sorption tests were instead conducted by including chamber 1. In this case, the gas mixture was prepared using mass flow controller type GM50A-013102RMM020 from MKS Instruments (full scale volumetric flow range of N2 100 cm STP 3 ), following the protocol proposed by Loianno and Mensitieri [29].…”

“…Mixed gas sorption tests were instead conducted by including chamber 1. In this case, the gas mixture was prepared using mass flow controller type GM50A-013102RMM020 from MKS Instruments (full scale volumetric flow range of N 2 : 100 cm 3 STP ), following the protocol proposed by Loianno and Mensitieri [29]. To perform a static sorption test, the gas mixture of desired composition was first prepared in chambers 1 and 2 and was subsequently let to expand in chamber 3.…”

“…At these frequencies, no IR bands associated with the polymer or with the absorbed species were present, so that the gas phase signals were well isolated and resolved and were used without any further treatment. The protocol proposed by Loianno et al was followed to calibrate these signals [11,29].…”

Sorption of CO2, CH4 and their mixtures in Amorphous Poly(2,6-dimethyl-1,4-phenylene)oxide (PPO)

“…Mixed gas sorption tests were conducted by including chamber 1. The gas mixture is prepared using thermal mass controllers type GM50A-013102RMM020 from MKS Instruments (full scale volumetric flow range of N2 100 sccm) following the protocol proposed by Loianno and Mensitieri [36]. To perform a static sorption test, the gas mixture of desired composition is first prepared in chambers 1 and 2 and is subsequently let to expand in chamber 3.…”

“…At these frequencies, no IR bands associated to the polymer or to the absorbed species are present so that the gas phase signals are well isolated and resolved and have been used without any further treatment. The protocol proposed by Loianno et al is followed to calibrate these signals [11,36].…”