Патент USA US2109235код для вставки
FehZÃ 1938. H. KQTT 2,109,235 RADIATION FILTER AND METHOD FOR UTILIZING THE SAME Filed June 29‘. 1935 -" TU» 4 2 Sheets-Sheet 1 f/W Ñeçenefaïeo/ Ce//a/ose l N V E NTOR .Haw/WANN KD7-r. _ BY Mmm ATTO RN EYS Feb. 22, 1938. 2,l09,235 H. KOTT RADIATION FILTER AND METHOD FOR UTIL'IZING TI‘IE SAME Filed June 29. 1935 2 Sheets-Sheet 2 ` 1276.' 5 5?/ Íf/ // 7 _ .40j /427 INVENTOR BY *ATTORNEYS Patented Felpa-2, 1938 2,109,235 UNITED STATES PATENT' oFFicE „ y 2,109,235 nimm'rlon m'rEn. AND ME'rnon Fon. U'nuzlNG 'run SAME Hermann Kott, East Orange, N. J., assigner, by mesme assignments, -to Ion Corporation, Short Hills, N. J., a corporation of New Jersey. Application June 29, 1935, Serial No. 29,095 1' claim. (ci. 25o-s4) This invention relates to radiation measuring ‘ by means of reiiector 2 through filter element 3 and detecting devices and more particularly to upon radiation sensitive device 4 which regulates radiation ñlter means for use in connection with the iiow of energy in external electric circuit 5 including meter 6 and source of direct electric the measuring and detecting o_f radiation. `One of the objects of the present invention is to provide a radiation ñlter for use in the de tection of radiation within certain wavelength ranges. Another object is to provide means for current 1. Radiation sensitive device 4 may be , any of the well known types of photo or radia tion sensitive cells or tubes heretofore proposed in the art. . Filter element 3 is comprised in accordance y -another object - is y with the present invention preferably of regen 10 10 tain wavelength ranges. Still to provide an improved method and means for erated cellulose impregnated with cobalt chloride. the detection and measurement of radiation. Regenerated cellulose contains a proportion of Other objects and advantages will be apparent glycerine approximating 14 to 16 per cent and is characterized by the property of absorbing mois as the invention is more fully disclosed. ture from an atmosphere and of giving up mois 15 In accordance` with these objects, I have dis 15 ture to the atmosphere relatively rapidly in re covered that Acellulosic material, particularly ra diation permeable cellulosic material such as re- y sponse to variations in themoisture content of generated cellulose, can be utilized as a radiation the atmosphere. The ultimate or equilibrium moisture content of the cellulose bears a substan iilter by incorporating within the cellulose a pro 0 portion of a'salt such as cobalt chloride which has tially constant ratio to the humidity of the at 20 mosphere with any given cellulosic material the property of changing its color or color in tensity with respect to its moisture content. which can be calibrated. The eiîect of tempera Thereafter by incorporating within the cobalt ture upon this constant ratio also may be cali ' impregnated cellulose suñicient water to impart brated. Accordingly, in the determination of atmos thereto a desired color intensity the material may detecting and measuring radiation within cer 25 be employed as a radiation ñlter. Upon the projection of radiation through 'the cobalt and moisture impregnated cellulosic ma terial upon a radiation sensitive device the said 30 device responds to and measures the amount of pheric humidity ñlter element 3 may be com prised for example of a relatively thin sheet of cobalt chloride impregnated regenerated cel lulose which is suspended in the atmosphere in such manner that the atmosphere will -freely such radiation which is not absorbed ‘by the iilter. contact with both faces. The beam of radiation This phenomenon may be utilized in a number A from source I may be focused to irradiate a rel atively large surface area of the filter element of different ways, and in the accompanying draw ings I have illustrated several adaptations. In and means (not shown) may be employedl to 35 the drawings Fig. 1 _illustrates schematically one focus the filtered beam upon the radiation sensi specific embodiment of the present invention; tive surface of photo-electric tube or cell 4. The amount of-cobalt chloride to be impreg Fig. 2vis a view along plane 2-2 of Fig. 1; Fig. nated in the radiation permeable cellulosic ma 3 illustrates schematically a second speciñc em terial may vary widely without departing essen tially from the nature and scope of the present invention, depending upon the contemplated- use embodiment of Fig. 3;` Fig. 5 illustrates schemati thereof. In the adaptation of the filter to the cally a second modiiication of the specific em use indicated in the specific embodiment of Fig. bodiment of Fig. 3; Fig. 6 is an enlarged sche maticl View of a further modiñcation of the em- -' 1 the intensity of'radiation and kind o'fradiation 45 bodiment of Fig. 3; Fig. '7 `is a view along plane emitted by source i may control the amount of 1-1 of Fig. 6; and Fig. 8 is an enlarged view of cobalt chloride required. So also the humidity range of the atmosphere may govern the amount one feature of the device of Fig. 6. Referring to Figs. 1 and 2, I have illustrated of cobalt chloride required. An ordinary incandescent ñlament lamp demits schematically as one speciiic embodiment of the 50 present invention an arrangement of elements radiation of a wide range of wavelengths.` The. color range in ñlter element 3 may be made to whereby the humidity or moisture content of at vary with variation in cobalt chloride content mospheres may be measured by utilizing the ñl and moisture content in the ñlter from very light ter element of the present invention. Radia rose to very dark purple thereby cutting oir or ' tion from source I, which may be an incandes 55 cent filament lamp as indicated. is projected as filtering out radiation having wavelengths with ‘ bodiment of the present invention; Fig. 4 illus 40 trates schematically a modiiication of the speciñc 2 2,109,235 in this color band. For the purpose of measur plate circuit to permit the adjustment of the cir ing the,l variations in the humidity of the at cuit resistances in each plate circuit so that with mosphere. the degree of accuracy sought may . any given grid voltage on grid I1 the current also control the color range employed. For ex drawn through tube I3 by both plate circuits ample, it may be desirable to obtain but three is substantially equal and potentiometer 22 there measurements such as low, medium and high humidity. In such case, the amount of cobalt chloride employed may be adjusted such` that Vwith high humidity the filter remains substan tially unchanged in color; with medium humidity the filter assumes color; and with low humidity the illter takes on a very dark color. For accurate measurement of the humidity. it is preferable to employ as a light source I a -15 special lamp which emits radiation relatively high in radiation oi' wavelengths within the color band of the filter 3. such as a. mercury arc, glow dis charge, or ultra-violet lamp. Such devices are readily available on the market today. With this kind of radiation passing through filter 3 the variations incident to absorption by the ñlter through changes in color due to moisture ab sorption from the atmosphere may be readily de tected and measured. 25 In the modiiication illustrated in Fig. 3 filter element 3 is enclosed within a housing 3 pro vided with radiation permeable windows 3 and I0 within which housing means II is provided whereby an atmosphere at a substantially con 30 stant humidity may be maintained. In this ar rangement, ñlter 3 thereby is given a determined color and is permeable to radiation oi' wave lengths below this color range. By projecting radiation emitted from source I through an 35 auxiliary filter 3' before passing the radiation through filter 3 a narrowedI band oi' radiation wavelengths thereby may be detected and meas ured by the external circuit 5 including means 6 and 1. Auxiliary filter 3', for example. may 40 exclude red and infra-red radiation and filter 3 may be colored by the humidity of the atmos phere enclosed within housing 8 to exclude all radiation above about 3100 Angstrom. Light source I, for example, may be an incandescent 45 filament lamp as shown or may be a tungsten mercury arc lamp emitting relatively large quan tities of radiation in the violet and ultra-violet range of wave-lengths. By the arrangement in dicated in Fig. 3 relatively accurate measure 50 ment of the amount of radiation below a certain wavelength (limited by the color imparted to fll ter 3) emitted during any given unit or period of time by light source I may be determined. In the modification illustrated in Fig. 4, the 55 detection and measurement of the radiation is obtained by the use of a radiation sensitive de vice I I and circuit means |2. Device || is substantially a gaseous conduc tion device and comprises an enclosing radiation permeable envelop II, a pair of spaced electrodes I3 and I4 and a pressure of ionizable gas. The electric circuit I2 includes means I5 to impress a potential upon electrodes I3 an'd I4 which is substantially less than the breakdown poten 65 tial therebetween; and means I6 to balance the external circuit resistance with the internal re sistance of the device I| to permit the ñow of a leakage current between the electrodes across the intervening gas path. 'I'his current flow is 70 impressed upon grid I1 of thermionic amplifier device I3 containing an indirectly heated cath ode rI3 and a. pair of anodes 20 and 2| which are electrically connected in parallely across poten tiometer 22 to a source of plate voltage 23. Var 75 iable resistances 24 and 25 are provided in each upon registers gere. " Thereafter//upon changing the internal re sistance by tube | I by projecting radiation there through in the manner indicated, the increase or decrease in current flow through device II var ies the potential upon grid I'I which in turn a1 ters the plate current drawn by the closer spaced plate electrode 2|. This is indicated by the de ilection in potentiometer 22 substantially as in dicated. In the modification indicated in Fig. 5, the ex ternal circuit I2 has been changed to provide for operation directly from an alternating cur rent source instead of a direct current source as indicated in Fig. 4. Rectiiler 23 energized by al ternating current from source 21 supplies a po- l tential of rectified current to resistance 28 pro vided with tap connections 29 and 30 from which potentials suitable to replace direct current sources I5 and 23 respectively may be drawn. 25 The remaining elements are substantially the same as those heretofore described in Flg.-4. In adapting the modifications of Figs. 4 and 5 to the detection and measurement of ultra-violet radiation, the structure indicated in Figs. 6, 7 30 and 8 has been devised. In Fig. 6 the radiation sensitive device II is shown totally enclosed by the filter heretofore identified by numeral 3, and hence is responsive to such radiation as may pass through the said filter. > 85 To obtain this result, I_comprise illter 3 of cup or closed end tubular shaped regenerated cellu lose material 3|, which is enclosed in a similarly shaped double walled radiation permeable hous ing 32 having an opening 33 in the base of the 40 outer wall which opens into a chamber 34 enclos ing a perforated container 35` which is filled with pieces or chips of regenerated cellulose. Filter 3| is impregnated with cobalt chloride as hereto fore described. Chamber 34 and the double 45 walled container 32 are sealed from the atmos phere but communicate with each other through opening 33. _ 'I'he open end oi' the double wall container 32 is inserted in groove 36 of base element 31 L50 wherein is concentrically located device II. 'I'hus assembled all radiation acting upon device II must pass through ñlter 3|. The color intensity of the ñlter 3| is adjusted by introducing within container 32 in any convenient manner an at mosphere having a humidity which with the co balt chloride content of the filter employed will color the ñlter 3| to pass radiation below about 55 2950 Angstrom. This atmosphere is retained therein until the illter 3| and regenerated cellu 60 lose particles in container 35 each have reached equilibrium as to water content by absorption from the atmosphere. The device then may be sealed from the atmosphere and within relatively large variations in temperature the color char 65 acteristic oi’ the filter 3| will remain substan tially constant'. The particles of cellulose in con tainer 35 act as a stabilirer as with variation in temperature they give up and absorb moisture from the atmosphere at a more rapid rate than 70 does the cobalt impregnated illter 3 I. 'I'his entire assembly of elements may be en closed in a radiation impermeable housing 38 provided with radiation permeable window 33 preferably of quartz, and the radiation to be 75 3 £109,285 measured projected through the window 3l upon ` and through filter 3| to device ll. The current flow in device Il is carried through terminals Il an 4I to any of the external circuits heretofore described. ~ _ ilcations and departures may be made therein without departing essentially from the nature and scope thereof. and all such modifications are contemplated as may fall within the scope or the following claim. - ' What I claim is: ¿radiation illter comprising a double walled and domed cylindrical container having an open radiationin the violet and ultra-violet range and ' ing in the domed outer wall thereof, a cylindrical and domed sheet of regenerated cellulose impreg 10 10 hence is of special service andutility in therapeu tic fields -wherein the application of ultra-violet nated with cobalt chloride enclosed thereby. a radiation inthe irradiation of food and milk hermetically sealed chamber closing said open products, the curative treating of persons and ing from the atmosphere said chamber` enclosing a perforated'container, a quantity of regenerated the like applications often require that the quan 1-6 tity and kind voi' radiation employed be known and cellulose within said container and a gaseous at mosphere having a determined humidity en controlled. ' ~ 'I'he device oi’ Figs. 6, 7 and 8 may be widely adapted to a variety oiuses. It is particularly adapted to the detection and measurement of Having broadly and speciñcally described the present invention it is apparent that many modi closed 'within said chamber and container. . HERMANN KO'I'I‘.