The objective of the invention is a method for reporting 5 foreign matter content in gas and an equipment therefor.

The detection of foreign matters often requires considerably expensive devices. When an army detachment e.g. is spreading out in an area, the detachment has its own analysis equip- 0 ment in a certain location. Reporting the measuring results of the analysis equipment to all members of the detachment is a problem, as everyone requiring the measuring results is not close enough to the analyzer to read the result of the detection. Therefore, even people being in the vicinity 5 should acquire their own device for the detection of foreign matters, if not in connection with the analysis device. The solution of providing everyone with an own detecting device for foreign matter content is however very expensive.

0 The US-patents 4119950 and 4668940 present conventional gas- warning devices for the transmissions of measuring data or alarm signals between two spots on building sites, oil rigs, etc. The objective of the US-patent 4119950 is monitoring the gas content. The apparatus according to the references, 5 comprises means for generating an audio-frequency electric signal. The transducers 2 and 4 operate as the transmitters and receivers of the ultrasonic waves. The transmitters are located to let the ultrasonic waves pass through the area in which the gas content is to be monitored. If a change in the 0 frequency from any of the circuits 22, 24, 26 is detected, the processor 34 can produce a corresponding radio-frequency output, which is fed to the transmitting aerial 38 for reception at a remote receiving station comprising an aerial 40, a receiver 42 and a display unit 44. There is nothing 5 mentioned about providing the receiver of the warning with a portable warning indication apparatus. This publication does not provide a solution to how different persons of a de¬ tachment could be rendered an alarm indication from one

detector .

The US-patent 4668940 relates to a portable electrically operable apparatus for monitoring and for giving warning of the presence of a predetermined environmental hazard. As one alternative is presented the including of a radio transmit¬ ter in special cases in the equipment. An uniquely coded signal can be sent to the central point when the alarm has been activated, thus alerting the Safety and Rescue Teams immediately. Signals indicating safe conditions could also be sent, if required. Two-way radio transmissions could be used to allow interrogation of the hazard monitoring and warning. The patent mentions the use of a radio transmitter for giving warning to the central point of the presence of a hazardous substance, detected by the monitoring device, to alert the rescue team. According to this the information about the detection is sent to one spot, and not separately to each member of the rescue team. The problem with the invention is supplying the information to all members of the team.

The method and equipment according to the invention provide a decisive improvement of the above mentioned disadvantages and problems. The embodiment of the method and equipment according to the invention is characterized in what is disclosed in Claims 1 and 5.

One of the most important advantages of the invention is that it provides a warning about the foreign matter content to a large group, e.g. a detachment, with only one detector for the foreign matter content. The warning is rendered immediately to everyone when the detector has reacted to the foreign matter or to its content. The warning can also be received when on the move. The warning detector is s all- sized.

The invention is below described with reference to the

enclosed drawings, in which

Fig. 1 presents a schematic illustration of the measuring equipment with a radio transmitter connected thereto.

Fig. 2 presents a schematic illustration of the arrange¬ ment according to the invention.

Fig. 1 presents a schematic illustration of an alternative detecting equipment of the foreign matter content, using e.g. the method presented in the Fl-patent 75055 for detect¬ ing e.g. combat gases. To define the foreign matter content in the gas in this method, the gas and its components are ionized in the ionization zone. They are led into a narrow analyzer channel, in which they due to the capillary effect have to pass in the middle of the channel. From there they are further deflected by electric fields causing unequal voltages to the electrode in the channel border, producing there the ion current. By the current spectrum based on ion currents, the different agents are identified and the ion contents in the gas is defined by comparing them to corre¬ sponding spectra obtained from standard samples of the different agents. A solution has also been disclosed, in which the ions contained in the gas are, before measuring, separated in a separator into positive and negative ions, of which ions of different brand are analyzed. Corresponding methods are presented in e.g. the DE-publication 202885, the EP-application publication 21 518 and the CH-publication 550 399. In the Fl-patent application 930122 is arranged in parallel or in sequence at least one ionization and at least one semiconductor cell simultaneously. The M90 detector of chemical substance, developed by the applicant or further developed versions of the same can be used to indicate the foreign matter content. The signal can be transferred even long ranges, according to the effects of the equipment, but e.g. 3-5 km is sufficient in army conditions and quite common depending on the form of terrain. The message can be

sent as a coded alarm signal. Both the transmitter and the receiver can be coded by an automatic code accumulator as often as possible. The user can choose the transfer protocol and the frequency. The alarm system can naturally be con- nected to the user's own wireless data transmission system.

In the equipment according to the invention, a conjunction is connected to the foreign matter detector 1, e.g. a radio transmitter 2 along a conventional data transmission cable 3, which radio transmitter is activated when the detector gives an impulse of detecting a foreign matter or a certain exceeding content. The carrier wave modulated in the radio transmitter is amplified and led to the transmission aerial 5, through which the data is transmitted as radio waves to the alarm units 4. The alarm unit 4 is a special radio receiver, which renders selectively an audible or visual alarm, or both. The alarm unit 4 is attached to the user's belt, or corresponding. The power sources are e.g. lithium batteries or accumulators. The alarm unit contains a device indicating low charging of the batteries or the accumulator. The signal indicating detection of a foreign matter content by the analysis device is sent to several portable receivers 4 simultaneously to alert all possessors of the receiver 5.

Fig. 2 presents how the people within the overlap of the radio transmitter can be alerted from one detector. The alarm devices of these people can be conventional remote pagers used in the radio telephone traffic, able to at least receive the signals of the detector's radio transmitter and render an alarm signal to its user. The device can also be developed so that a certain gas or content gives a different message to its user to make him react correctly. The user's paging device is adapted to identify only the signal re¬ ceived from the detecting device.

The invention has been described with reference to only one of its favorable examples of embodiment. The solutions and drawings presented above are only examples, and the inven-

tion is not to be considered as so limited, but all modifi¬ cations within the scope of the inventive idea characterized by the claims are feasible.