DD151362A1 - DOSIMETERS FOR THE SPECIFIC DETERMINATION OF METAL DAMAGES IN GASES - Google Patents

Abstract

The dosimeter for the specific determination of mercury vapor should be able to be used in many areas of economics and in particular in environmental and health protection. Its essence is that it needs no device for a defined, constant negative pressure. It is characterized by the specific absorption of mercury vapor after it has passed through a calming and a defined free diffusion path. It is characterized by simplicity, small size and weight as well as easy to realize.

Description

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Title of the invention

Dosimeter for the specific determination of metal vapor in gases.

Field of application of the invention

The invention relates to a device for the determination of metal vapor, in particular of mercury vapor in gases, which allows a very long analysis time v / care free · Application is the entire gas technology and in particular the environmental and health protection.

Characteristic of the known technical solutions

Previously known solutions are characterized, on the one hand, by the fact that they are quantitatively reduced to metals, e.g. Mercury to be examined gas by means of vacuum and in a defined amount by an absorption device is sucked (DDR standard, TGL 32600, sheet 07). Resulting mowing gels are: high equipment requirements, extensive maintenance during the analysis time, considerable personal strain on portable devices and limited analysis times.

On the other hand, a solution for mercury vapor is known (CS McCammon, Jr., JW Woodfin: An evaluation of a passive monitor for mercury vapor, Amer, Ind. Hyg. Assoc. J. 3Q (1977) 8, 378-386), in one goldfolio in one

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permeable film is melted, whereby the defined permeation of mercury is to be guaranteed. Their shortcomings arise from the fact that the slightest leaks make a quantitative analysis impossible and the permeated amount of steam is very small; If this device is also worn on clothing, there is a risk of capturing mercury, which evaporates from the textile fabric and thus does not reflect the actual concentration in the air. The use of gold foil is also economically unreasonable. None of the solutions found permits the use of many devices for detecting the mercury exposure of large groups of subjects.

Object of the invention

The aim of the invention is a device for the specific determination of metal vapors, which allows a statement on the product of analysis time times concentration, requires very little technical and maintenance effort, is easy to implement, has small dimensions and low weight and the subject's exposure to personal dosimetry particularly strong reduced.

Explanation of the essence of the invention

The invention has for its object to use for measuring mercury vapor in gases, a device that requires no negative pressure and indirectly directs the gas stream to be analyzed at the beginning of a diffusion path.

Their features according to the invention are: a calming section for directed gas streams, followed by a diffusion path defined and free for

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Gases and vapors, and at the end of which is a suitable for the metal absorption medium of sufficiently high capacity. The calming section consists of either an intermediate device for generating a Strömungswider- state or it is designed so that a direct flow against the opening of the diffusion path is prevented. The metal vapor enters the device in the stated sequence and is determined separately on the absorption medium in a manner known per se. The device is calibrated with test gas containing appropriate amounts of mercury vapor, the detection of the product from analysis time to concentration is guaranteed.

embodiment

The invention will be explained below using an exemplary embodiment for the determination of mercury vapor. On the sides of a small plate there are two semicircular stirrups. These are covered with suitable textile material so that a completely covered space is created above the base plate. Central to the base plate is an open container attached, which fixes the calming section through its outer dimensions, through its inner the diffusion section. At the bottom of the container, the absorption medium, for example, a noble metal-coated metal foil is installed. The container is closed with a cap and provided at its opening with a porous layer that does not hinder the diffusion. The device according to the invention can be dimensioned so small that they serve on the clothing of a subject aufschlag) can be worn without further notice. By

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Choice of a correspondingly large diffusion distance can be achieved a wide range of applications for very different concentrations and analysis times »

Claims (1)

_ ₅ _ 2 2 17 5 4 invention claim 1. Dosimeter for the specific determination of metal vapor, in particular of mercury vapor, in gases, characterized in that a defined, free diffusion path for the test gases is arranged in front of an absorption layer and that the dosimeter has a calming section against a direct flow against the opening of the Diffusion path has « 2о dosimeter according to item 1, characterized in that the calming section is formed either of an intermediate device for generating oines, ^ resistance or so that a direct flow against the opening of the diffusion path is prevented.