Micro-ionisation sensor to detect pollutants in air - comprises ion source, gas passage, ion path, control system, collector electrodes, amplifier and conductor system formed within cylindrical semiconductor element

摘要

In a new micro-ionisation sensor for determining the composition of gas mixtures, the gas molecules are ionised and separated by an electric field in accordance with their drift velocity, and are then collected and registered on one or more collector electrodes (D) in a sequential series. The ion streams are amplified by means of a fast amplifier (1), and the drift times, peak heights, and half period widths are determined. The molecules are identified from their drift times, and the molecular concentrations are determined from the peak areas. The ion sources (A), gas inlet and outlet (H), drift path (C), control system (B), collector electrodes (D), preamplifier, and conductor path system are incorporated in a semiconductor material in a monolithic or modular manner, and the material preparation is in accordance with the processing techniques of micromechanics and microelectronics. USE/ADVANTAGE - Used for simultaneous determination of the concentrations of the constituents of gas mixts. esp. air, including the concns. of health- and environment-damaging trace elements. The sensor, which ionises the substances to be measured, separates the ions at atmospheric pressure and simultaneously displays (G) their concentrations, is effectively miniaturised.