US2490642A - Method and apparatus for physico-chemical analysis - Google Patents

Description

Dec. 6, 1949 1 LIPSQN 2,49%,642

METHOD AND APPARATUS FOR PHYSICO-QHEMICAL ANALYSIS Filed NOV. 7, 1945 7 VOLTAGE /0 SOURCE I 1 q :2 4/ 3 2 I I "5 il f I BOMBARDING l LINEAR MULTI- PULSE CHAMBER 2 I AMPLIFIER VIBRATOR INTEGRATOR FIGZ.

RECORD RECORD RECORD F|G.3 Hea FIG-3 RECORD RECORD RECORD D D -D Fles F103 FIG.3

RECORD INVENTOR WWW LEONARD B. LIPSON D I F102, 7 BY M ATTORNEY Patented Dec. 6, 1949 METHOD AND APPARATUS FOR PHYSICO- CHEMICAL ANALYSIS Leonard B. Lipson, Houston, Tex., assignor to The Geotronics Corporation, Dallas, Tex., a corporation of Virginia Application November 7, 1945, Serial N 0. 627,227

This invention relates in general to certain new and useful improvements in methods and apparatus for physico-chemical analysis and, more particularly, to methods and apparatus for the detection of radio-active and hydrogenous materials in soil samples and the like.

It has been experimentally shown that the rad o active content of a surface soil sample as well as its hydrocarbon content may be correlated with substerranean petroleum deposits. Soil and similar substances containing minute quantities of radio active and hydrogenous materials cannot, however, be accurately analyzed by ordinary schemes of analysis in the absence of time-consuming attenuated procedures, and, furthermore, entirely separate analytic procedures and apparatus must be employed for the determination of radio-active materials on the one hand and hydrogenous materials on the other hand. Thus, when prospecting for petroleum and the like by analyzing the radio-active and hydrogenous content of a surface soil sample, it is more convenient and econom cal to use a single apparatus for performing both of the requisite analytical determinations.

It is, therefore, a principal object of the present invention to provide a simple, rapid, and definitive method for the analytical determination of radio active and hydrogenous materials, and apparatus for carrying out the same.

It is also an object of the present invention to provide compact and economical apparatus for analytically determining the radio active content of a sample.

It is a further object of the present invention to provide compact and economical apparatus for analytically determ ning the content of hydrogenous material in a given sample.

In the drawing:

Figure 1 is a vertcal sectional view of a bombarding chamber for detecting the radio active content of a sample and for exposing said sample to radiations of selected wave length;

Figure 2 is a diagrammatic representation of a preferred form of apparatus for the analytical determination of radio active and hydrogenous materials in accordance with the methods of the present invention.

Figures 3 3 3 and 3 are graphs or charts showing examples of the analytical results obtainable with the methods and apparatus of this invention.

Referring now in more detail and by reference characters to the drawings, A designates a bombardment chamber comprising a preferably light- Claims. (Cl. 25083.6)

proof rectilinear box b having walls p formed of a relatively thick plywood or other similar material. Suitably disposed within bcx b is an opentopped sample container I for holding a sample 8. Suitably mounted within the box I) is an ultra-violet light source 3 having leads 4 and 5 connected to voltage source 0. Also disposed within box b to receive fluorescence rays R and R given 01f by the sample 8 upon bombardment by ultra-violet light rays 1' and 1-, is a detector tube 6 comprising a self-extinguishing tube of the Geiger-Muller type, consisting of a cylindrical element 1 having a small aperture 8 centered midway along its length, and a wire 9 extending CO-a a Y hrough element 1. Lead ill extends through the walls of box I) and connects to wire 9. Lead l extends through the walls of box 22 and connects to element 1. The detector tube 6 is constructed of ultra-violet transparent glass, that is to say, a glass which passes or transmits a relatively large quantity of ultra-violet as well as visible light, Element 7 is coated on its inner surface with a material which freely gives up electrons when bombarded by radiations of the correct wave length.

The lead H issuing from the chamber A is connected to one input lead of a high-gain linear amplifier B and to the ground. The lead I0 is connected through resistor I2 to a source of high voltage and is also connected through the capacitor l3 to the other input lead of the amplifier B. This source of high voltage is maintained just above the threshold voltage of the detector tube 6 so that such tube 6 is in its most sensitive operating condition for the detection of radiant energy entering therein. The output leads of the linear amplifier B are connected to the input leads of a multi-vibrator C, the output leads of which are connected to the input leads of a pulse integrator I). The output leads of pulse integrator D are connected to the input leads of a suitable type of direct reading instantaneous recorder E, all as best seen in Figure 2.

In performing an analysis, a sample of soil or other material containing radio active or hydrogenous material, or both, is carefully mulled or ground to a substantially uniform state of fineness and dried under a carefully controlled moderate temperature so as to remove all traces of moisture. It is essential that the sample be thoroughly dried or that all the samples in a single survey be dried to the same degree to insure uniform test conditions. Because of the danger of contaminating the sample with water vapor picked up from the atmosphere, it is preferable that sample 3 be packed in sample containers prior to drying. When dry, sample container I together with sample 8 is weighed and then placed within box A.

The ultra-violet light issuing from light 3 in rays r, r bombards sample s. It sample s contains hydrogenous material, such material will fluoresce when so bombarded and rays R. R will issue toward the detector tube 6 and enter cylinder 1 through aperture 8. Since the inner surface of cylinder 1 is coated with a photo-sensitive substance, electrons are freely given up and attracted by wire 9. The electrons will create impulses which will pass throughlinear amplifier B, multi-vibrator C, pulse integrator D, andgive a visible record on recorder E The detector tube 6 actually counts the photoemitted electrons, and thus, it is obvious that much smaller values of fluorescence can be measured with detector tube 6 because it is more sen sitive than an. ordinary phototube. Since ultraviolet transparent glass is usedin the manufacture of detector tube- 6, it is. capable of detecting fluorescence in the visible range or near ultraviolet region, as well as the full range of ultraviolet wave lengths.

Furthermore, the detector tube 6 is uniquely capable of detecting radio activity as well as fluorescence. light 3 is bombarding sample s, and sample s contains radio active as well as hydrogenous material, the record on recorder E will be a composite one of both radio activity and fluorescense. Figure 3 shows a profile taken over an area which contains radio active as well as hydrogenous substances. This compos te curve may be resolved into two components, one the contribution of radio active material, and the other the contribution of hydrogenous material, by disconnecting source 1; from light 3 and noting the record on recorder E. The record shown will be that of radio activity only, since no fluorescence will be evident in the absence of ultra-violet light. Figure 3 shows this profile. in Figure 3 is subtracted from the curve in Figure '3, the curve in Figure 3 isthe result. This curve is the result of fluorescence only.

Figures 3 and 3 show profiles made under the similar conditions to those of Figure 3*, that is to say, placing difierent samples in the sample container and bombarding it with rays 7, r, employing the same hookup employed in the example above discussed. For purposes of discus sion, let it be assumed that the curves shown in f Figures 3 and 3 respectively. are the type of curves obtained fromtwo different samples and that corres ondingly the curves of Figure 3 and 3 respectively, are obtained when the source 1! is disconnected. scrutinizing Figures 3 and 3 which are companion curves, it becomes evident that the anomaly shown in the curve of Figure 3 is due to fluorescence only, since no anomaly occurs in the curve of. Figure 3 Similarly, it is evident that, the anomaly of Figure-3 is due to radio activity only, since the curve of Figure 3 is identical to it in every respect.

In order to relate the results to actual figures and percentages,.the apparatus must, of course, 7

Thus, it can be seen that when If the curve While I have described my invention in certain specific embodiments, I do not desire to be limited thereto, as for example, the material examined does not have to be a surface soil sample, but may be well cuttings or cores or any material suspected to contain radio active and hydrogenous materials.

It should be understood that changes in the methods, compositions and combinations above set forth may be made without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. A method for use in petroleum exploration, which method comprises thoroughly drying a soil sample andreducing it to a substantially uniform state of subdivision, irradiating the sample directly with ultra-violet light, measuring the intensity of the total radiations given off by the sample, thereupon stopping ultra-violet radiation, and measuring the inherent radiations coming from the sample to ascertain the radio activity of the sample.

2. A method for use in petroleum exploration, which method comprises drying a soil sample, directly irradiating the sample with ultraeviolet light,. measuring the intensity of the total radiations given off by the sample, thereupon stopping ultra-violet radiation, and measuring the inherent radiations coming from the sample to ascertain the radio activity of the sample.

3. Apparatus for analyzing soil samples incident to petroleum exploration to determine the content of radio active and hydrogenous materials in the samples, said apparatus comprising a bombardment chamber having an ultra-violet light source, means in the chamber below and to one side of the light source for exposing a surface of the sample to rays fromsaid source,

and an electronic tube positioned outwardly from the sample along a line normal to the. samplesurface for sensing the total radiations given off by the sample when irradiated by ultra-violet light.

4. Apparatus for analyzing soil samples in cident to petroleum exploration to determine the content of radio active and hydrogenous materials in the samples, said apparatus comprising a bombardment chamber having an ultraviolet light source, means in the chamber below and to one side of the light source for exposing a surface of the sample to rays from said source, and an electronic tube of the Geiger- Miiller type positioned along a line normal to said sample surface for sensing the radiations given off by the sample when irradiated by ultra-violet light.

5. Apparatus for analyzing soil samples incident to petroleum exploration to determine the content of radio active and hydrogenous materials in the samples, said apparatus comprising a bombardment chamber having an ultra-violet light source, means in the chamber belowand to one side of the light source for exposing a surface of the sample to raysfrom said source, an electronic tube positioned along a line normal to said sample-surface for sensing the combined effect of the radiations given off by the sample and the radiations produced by irradiation. of the sample with ultra-violet light and an electronic circuit for measuring the radiations sensed by the tube.

6. Apparatus for analyzing samples to determine the content of radio active and hydrogenous materials in the samples, said appara- 7. Apparatus for analyzing samples to determine the content of radio active and hydrogenous materials in the samples, said apparatus comprising a bombardment chamber having an ultra-violet light source, means for exposing the sample to rays from said source, and an electronic tube having a central rod-like electrode surrounded by a tubular photo-sensitive electrode having an aperture presented toward said means, said tube being positioned for sensing the combined effect of the radiations given oil. by the sample and the radiations produced by the irradiation of the sample with ultra-violet light.

8. Apparatus for analyzing samples to determine the content of radio active and hydrogenous materials in the samples, said apparatus comprising a bombardment chamber having an ultraviolet light source, means for exposing the sample to rays from said source, and an electronic tube having a central rod-like electrode surrounded by a tubular photo-sensitive electrode having an aperture through which radiations may reach the rod-like electrode positioned for sensing the combined effect of the radiations given off by the sample and the radiations produced by the irradiation of the sample with ultra-violet light.

9. A method for use in petroleum exploration, which method comprises thoroughly drying a soil sample and reducing it to a substantially uniform state of subdivision, irradiating the sample directly with ultra-violet light while maintaining the sample out of contact with moisture and moisture-containing atmosphere, measuring the intensity of the total radiations given ofi by the sample, thereupon stopping ultra-violet radiation, and measuring the inherent radiations coming from the sample to ascertain the radio activity of the sample.

10. A method for use in petroleum exploration, which method comprises thoroughly drying a soil sample and reducing it to a substantially uniform state of subdivision, placing the dried sample in a substantially moisture-proof chamber, irradiating the sample directly with ultra-violet light, measuring the intensity of the total radiations given 011 by the sample, thereupon stopping ultra-violet radiation, and measuring the inherent radiations coming from the sample to ascertain the radio activity of the sample,

LEONARD B. LIPSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Nmnber Name Date 2,141,655 Kott Dec. 27, 1938 2,161,859 Geficken et a1 June 13, 1939 2,305,082 Hocott Dec. 15, 1942 2,311,151 Campbell Feb. 16, 1943 2,330,829 Lundberg Oct. 5, 1943 2,351,028 Fearon June 13, 1944 2,359,135 Lynton Sept. 26, 1944 2,394,703 Lipson Feb. 12, 1946 2,398,934 Hare Apr. 23, 1946 FOREIGN PATENTS Number Country Date 705,749 Germany May 8, 1941 OTHER REFERENCES Locher: Physical Review, vol. 42, pp, 525-546 (rsum of disclosure on page 525) Nov. 15, 1932.

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