Tunable Diode Laser Absorption Spectroscopy Sensor for Calibration Free Humidity Measurements in Pure Methane and Low CO Natural Gas.

We report a new direct tunable diode laser absorption spectroscopy (dTDLAS) sensor for absolute measurements of HO in methane, ethane, propane, and low CO natural gas. The sensor is operated with a 2.7 µm DFB laser, equipped with a high pressure single pass gas cell, and used to measure HO amount of substance fractions in the range of 0.

Preparation of calibration gas mixtures for the measurement of breath alcohol concentration.

Calibration gas mixtures for breath alcohol measuring techniques need to have a defined ethanol concentration in water-saturated air. For the calibration of evidential breath analysers in Germany, these gases are prepared at the Physikalisch-Technische Bundesanstalt according to the saturation method. The ethanol concentration is calculated via the air-liquid partition ratios of the air-water-ethanol substance system.