Abstract: The invention relates to a method for determining the gas quality of a sample gas mixed at least in part with biogas, having the main components CH4, CO2, N2, O2, H2, proceeding from a spectrum of the sample gas determined by means of infrared-spectroscopy measurement methods, under operating conditions, from which the mole ratios of the sample gas are determined by means of correlative methods, and converted to characteristic variables of the gas quality.

Abstract: The invention relates to a method for determining the gas quality of a sample gas mixed at least in part with biogas, having the main components CH4, CO2, N2, O2, H2, proceeding from a spectrum of the sample gas determined by means of infrared-spectroscopy measurement methods, under operating conditions, from which the mole ratios of the sample gas are determined by means of correlative methods, and converted to characteristic variables of the gas quality.

Abstract: The invention relates to a method for determining the gas quality of a sample gas having the main components H2, CO, CO2, N2, CH4, proceeding from a spectrum of the sample gas determined by means of infrared-spectroscopy measurement methods, from which the mole fractions of the sample gas are determined by means of correlative methods, and converted into characteristic variables of the gas quality.

Abstract: The invention relates to a method of determining mainly the compressibility number K, the standard volumetric gross calorific value Hv,n and the standard density ?n of test gases using values determined from a spectrum of the test gases. The invention describes various approaches of translating the values for determining the desired values using the data of the spectrum in the operational condition to the standard reference condition using two-step iteration processes without having to subject the test gases to time-consuming treatments. The invention further relates to devices for determining the values required for the methods and which further develop devices for carrying out the methods.

Abstract: Analysis device for determining an analyte in vivo in the body of a patient, having a measuring probe with a hollow needle (18) which can pierce through the skin. Light is passed through the hollow needle (18) and into the body via an optical fiber (22) travelling in the hollow needle (18). The light transported in the optical fiber (22) is modified in the measuring probe (3), the modification being characteristic of the presence of the analyte. A measurement and evaluation unit (4) measures the change to extract information concerning the presence of the analyte in the body.

Abstract: A photometric device and method for determining the gross calorific value of a test gas, especially natural gas having a radiation source that produces a measuring beam and a modulation unit to modulate the measuring beam. A test cell with test gas and a receiver for the beam are arranged successively in the path of the measuring beam. The measuring signals of the receiver are supplied to an evaluation unit that includes at least one signal amplifier for the amplification of the signals. The signal amplifier is provided with adjustment devices to adjust the signal amplifier according the spectral properties of the measuring beam. The gross calorific value of the gas is indicated by the sum of the amplified measuring signals produced in a computing machine.

Abstract: A procedure for the determination of the quality of gas of a probe gas, in particular a burnable gas, using a transmission spectrum of the probe gas determined at operating conditions by means of spectroscopical methods of measurement. At least the associated values of the pressure p and the temperature T of the probe gas are determined and in a number of selected spectral regions at least one spectral vector is constituted by integrating quantities of the transmission spectrum of the probe gas, which shows as components the values of the integrals with respect to the selected spectral regions and is characteristic for the properties of the probe gas at operating conditions.