METHOD FOR DETECTION OF ALIEN MATTER CONTENTS IN GASES

Abstract: A method for detection of alien matter content in gas, in which method the gas and the materials contained in it are ionized in an ionization room (1). The present methods are inaccurate and unreliable. The invention is based on a method, in which the ionized gas is led through chambers (2) containing different electric fields, out of which at least from one the through the chamber passed field current is measured, from which a signal is obtained, which describes the existence of alien matters in the gas. More parameters are obtained for detection of different materials by measuring favourably the currents passed through several electric field chambers as well as possibly by branching off from the ionization source the flow to different analysis lines of the electric field chambers.

Description: METHOD FOR DETECTION OF ALIEN MATTER CONTENTS IN GASES The objective of the invention is a method for detection of alien matter contents in gases, in which method the gas and the materials contained in it are ionized in an ion¬ izing room. For many different purposes it is endeavoured to detect and to measure the contents of alien matters contained in gases. In particular when analyzing from the gas some re¬ latively small quantities containing components, the im- purities of the gas may disturb the detection. The detec¬ tion of different molecules or molecule groups performed from gases in general, from gases attenuated by vacuum pumps or from vapour originating from evaporated solid materials or liquid matters are nowadays connected with problems. In particular the poisonous materials existing in the air, such as from the industry by accident into the air emanated poisonous matters or into the breathing air diffused nerve and other kinds of combat gases, are difficult to detect in a quick and dependable way. At the moment mostly is used by taking advantage of the analyzing methods the EC-detector of gas chromatographs , in which method the radioactive radiation is allowed to ionize the carrier gas and the molecules of the alien mat- ters contained in it, the ionized molecules of the carrier gas are permitted partly by means of delaying to recombine themselves, whereafter the iones of the gas are measured. In such a manner for instance is obtained the signal to be measured of the organic substances evaporated into the carrier gas. Measuring devices based on this same prin¬ ciple have also been designed for analyzing of nerve gases from the air. These devices are of two categories: in the first application the ionized molecules are led into a lab¬ yrinth, where the own molecules of the air are allowed to recombine themselves and the current of iones caused by the organic molecules is measured after this. In the other application the entering of the light air molecules into the ione measuring space is impeded by means of voltage grids. This in use being method and the devices for ap- plication of it are not sensitive enough when measuring low concentrations such as nerve gases or corresponding from the air or they give a signal also for the other ma¬ terials or impurities contained by the gas, such as to¬ bacco smoke, exhaust gases, explosion gases, protection smokes etc. substances. Additionally, the cause of the signal can also be for instance a sudden increase in the moisture content of the air, so the measuring outcome is inaccurate and uncertain. The aim of the invention is to bring about a method, by means of which from a gaseous state different alien mat¬ ter components, their quality and quantity, existing in the gas are measured and detected. In particular the pur¬ pose of the invention is to bring forth a method of de- tecting even a small amount of substance amidst the pos¬ sibly disturbing other quantities of materials and impu¬ rities in a dependable and a quick way. In addition the aim of the invention is to bring about a method of de¬ tection in particular of dangerous matters, such as for instance nerve gases or corresponding, and the detec¬ tion and measuring of the consistence and the quality of these materials. The aim of the invention is achieved by means of the method, for which is characteristic that, what has been presented in the patent claims. According to the invention the gas and the materials con¬ tained by it are led through chambers with different elec- trie fields and an at least through one chamber passed field current is measured, whereby out of the measuring a signal is obtained, which describes the existence of alien matters in the gas. The whole gas is first ionized and thereafter the flowing gas is treated in different elec¬ tric fields. At least in one electric field chamber the current between the voltage plates is measured. After that the ionized gas flow has been treated in different electric fields, it is possible to analyze already in one current measuring for instance high molecule organic molecules from the air. A characteristic feature of the invention is, that the moving and the recombinating ability of different molecules is taken advantage of in different electric fields, when the whole of the gas has first been ionized. The method is functioning under atmospheric pressure or in an underpressure, for instance in air thinned by a vacuum pump. The method can also be used in many differ¬ ent chemical analyzing methods, such as in detector of gas chromatograph or in detector of liquid chromatographs, when the materials first are heated or brought into a gaseous state by lowering the pressure. In such a -way more resolu¬ tion capacity is brought into the analyses. With the help of the method in accordance with the invention it is also possible to measure concentrations from a wished group of materials and additionally divide the group into subdivi¬ sions, for instance in order to determine the quality of the nerve gas . In a favourable application of the method from two or more chambers with different electric fields the passed-through flows are measured and the analysis of the materials to be examined is made on basis of the quantities and relations of the flow signals. Hereat different molecule groups can be separated from each other with the help of typical flow signals from different spots. In the following the invention is explained more indetail by referring to the attached drawing, in which figure 1 presents an application of the device system for realization of the method in accordance with the invention in cross-section and seen from the side, and figure 2 presents an other application of the device sys- tem for the applying of the method in accordance with the invention in cross-section and seen from the side. In the in figure 1 presented application the principle of the method in accordance with the invention has been pre- sented. To the device system belong the ionization room 1, the chambers 2 and the meters 3. Into the chambers 2 has been formed with the voltage plates the traverse elec¬ tric fields 6 of different magnitude. In the ionization room a suitable radio isotope is used, with the help of the radiation of which the ionization of the gas is taking place. The gas to be examined is brought in this applica¬ tion in by suction through the intake opening 4 to the ionization room 1 and from there the ionized gas is led through the chambers placed after each other through the outfeed opening 5 out of the device system. The flow is obtained in this application by means of an air pump, by which the gas and its componenst are sucked through the analyzing device system. In the ionization room the ioniz¬ ed molecules and the fragmented molecules are transported through the chambers and through the different electric fields existing in the chambers. Hereby the molecules en¬ deavour to recombine themselves or to destroy their charges and in the different electric fields also iones are removed from the system. In the figure the voltages form together with the earth coupled lower plates field lines into the passage s'pace , and when the intensifiers 3 are coupled to the ground current, it is possible to start treating the signal. By setting two or more flowing measurings in the same flowing channel can at using of electric field of dif- ferent magnitude different molecule groups be separated from each other with the help of typical flow signals from different spots. By observing the flow signal values characteristic for each molecule group the observation and measuring result is obtained. In the application presented in figure 2 the ionization room 1 is in the middle of a mainly sheet-formed body, where the chambers are placed on both sides of the ioniza¬ tion room side by side. To the ionization room several chambers are connected radially or at least channels form¬ ed by one chamber. In this application the walls of the chamber are formed by the voltage plates 2 and between the voltage plates the measuring plate 7 is placed. The measur¬ ing plate is divided into parts and placed between the vol¬ tage plates in such a manner, that the distance between it and the voltage plates varies. Hereby has between the voltage plates been formed at least/minor chambers, the electric field intensity vary from each other. The gas to be examin¬ ed is led out from-the ionization room by changing the route of the gas on the different sides of the measuring plate by taking advantage of the openings in the measuring pLate. The parts of the measuring plate are fixed to the one of the voltage plate. From the measuring plates the current is measured against the ground with the help of the intensifiers 3. From the ionization room leave several measuring channels (on the figure two channels) and the voltage plates are in different potentials in regard of the measuring plate 7. Hereby it is possible to start measuring signals right after the ionization, for instance in opposite electric fields against the ground. The alien matter content can be detected and measured by leading ionized gas into the channels of the device system, in which there are chambers with different electric fields, and by measuring the through the chambers passing field current the measuring values are obtained. One advantage of the structure presented in figure 2 is, that the measuring spots can be made for instance directly on the electronic circuit card and the voltage plates are on top of the insulations acting as protective sheets for the structure. With the help of this kind of a two-channel analyzer it is possible to measure concentrations of nerve gases, which are below even 0.1 mg/cu.m, when usually as 5 an alarm limit for instance for sarine is considered 0.5 mg/cu.m. The false signals caused by tobacco smoke, com¬ bustion gases, explosion gases and protection smokes can be eliminated with this kind of multimeasurin . ID! The invention is not limited to the presented favourable application modes, but it can be transformed within the frames of the attached patent claims. The invention is not connected only with the analyzing of the nerve gases from the air, but ir can be used for detection and analyz- 15 ing of different molecules and molecule groups performed from gas in general, from gas attenuated with the help of a" acuum pump as well as from vapour of evaporized solid or liquid substances.

Claims: CLAIMS 1. Method for detection of alien matter content in gases, in which method the gas and the materials contained in it are ionized in an ionization room (1), c h a r a c t e r - i z e d in, that the gas and the materials contained in it are led through chambers (2) with different electric fields (6) and the field current passed through at least one chamber is measured (3), whereat from the measuring a signal is obtained, which describes the existence of alien matters in the gas. 2. Method in accordance with the patent claim 1, c h a r ¬ a c t e r i z e d in, that from two or more chambers with different electric fields the flows passed through them are measured and on basis of the amount and relations of the flow signals the analysis of the materials to be ex- amined is made. 3. Method in accordance with the patent claim 1 or 2, c h a r a c t e r i z e d in, that the ionized gas is led to chambers arranged after each other, from which the through them passed flows are measured. 4. Method in accordance with the patent claims 1 or 2, c h a r a c t e r i z e d in, that the ionized gas is led into at least two, side by side arranged, from at least one chamber formed channel, and on basis of signals obtain¬ ed from the measuring signal of at least one chamber of each channel the analysis is made. 5. Method in accordance with the patent claims 1 or 2, c h a r a c t e r i z e d in, that the ionized gas is led to pass between the in the chamber (2) placed, into parts divided flow measuring plate (7) and the chamber wall form¬ ing voltage plates varying the route of the gas on differ- ent sides of the measuring plate and the distance of the measuring plate from the voltage plate varying two or more minor chambers are formed in the chamber, the intensity of the elecric field of which are different from each other.

Inventors: PUUMALAINEN PERTTI, PUUMALAINEN, PERTTI
Applicants: PUUMALAINEN PERTTI, PUUMALAINEN, PERTTI
Application year: 1987
Main classification: G01N27
IPC codes: G01N27