US2122222A - Device for automatic interruption of radiation - Google Patents

Device for automatic interruption of radiation Download PDF

Info

Publication number
US2122222A
US2122222A US748151A US74815134A US2122222A US 2122222 A US2122222 A US 2122222A US 748151 A US748151 A US 748151A US 74815134 A US74815134 A US 74815134A US 2122222 A US2122222 A US 2122222A
Authority
US
United States
Prior art keywords
tube
grid
electrode
cathode
condenser
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US748151A
Other languages
English (en)
Inventor
Vingerhoets Antonius Wilhelmus
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Application granted granted Critical
Publication of US2122222A publication Critical patent/US2122222A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J47/00—Tubes for determining the presence, intensity, density or energy of radiation or particles
    • H01J47/02—Ionisation chambers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/15—Instruments in which pulses generated by a radiation detector are integrated, e.g. by a diode pump circuit
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/26—Measuring, controlling or protecting
    • H05G1/30—Controlling
    • H05G1/38—Exposure time
    • H05G1/42—Exposure time using arrangements for switching when a predetermined dose of radiation has been applied, e.g. in which the switching instant is determined by measuring the electrical energy supplied to the tube
    • H05G1/44—Exposure time using arrangements for switching when a predetermined dose of radiation has been applied, e.g. in which the switching instant is determined by measuring the electrical energy supplied to the tube in which the switching instant is determined by measuring the amount of radiation directly

Definitions

  • the present invention relates to devices for the automatic interruption of the radiation caused by X-rays, gamma rays etc., after such radiation has produced a desired effect, for instance, a sufficient exposure (blackening) of a photographic plate.
  • My invention will be described in its application to the taking of X-ray exposures.
  • She condenser biases the grid of a triode, the plate circuit of which controls, by means of a switch, the operating circuit of the X-ray tube; whereby upon loss of charge of the condenser, the increased plate current of the triode causes the actuation of the switch and the interruption of the operating circult of the X-ray tube.
  • the present invention has for its objectto avoid such deleterious and accidental influences of leakage outside of the ionization chamber, and to thereby provide a device of this kind which is reliable and accurate.
  • the condenser is charged through the vacuum tube to the grid of which it is connected, thereby avoiding the lead connecting the grid and the corresponding electrode of the condenser to a terminal of the charging source. This eliminates an important source of leakage.
  • the ionization chamber itself is formed as to constitute the condenser.
  • the electrodes of the ionization chamber are given a sufficiently large area as to give the required capacity. This causes the elimination oi further leakage sources.
  • This increased insulating resistance makes it possible to use a much smaller capacity, which increases the sensitlveness of the adjustment.
  • the ionization chamber is rigidly connected to the vacuum tube by a tube of insulating inateriai which encloses the connecting lead between the grid and the ionization chamher, which tube is preferably exhausted.
  • the ionization chamber and electron relay may thereby constitute a single device.
  • the insulating member supporting the two electrodes of the ionization chamber can be intercepted by a conductive zone to which zone a negative potential may be applied, which potential may be that 01' the grid or may be still lower. This permits compensation of the leakage between the grid and the cathode (which is positive with respect to the grid).
  • the same source can be used to charge the ionization chamber (condenser) and to supply the plate current for the electron relay.
  • Such source may be, for instance, a rectifled alternating current, which is preferably filtered, and across which is connected a potentiometer, from which the various desired voltages can be tapped off.
  • a gas discharge path may be provided.
  • a discharge path has a definite ignition voltage, the voltage applied on the device does not vary when the voltage of the supply mains shows an incidental increase.
  • the condenser is charged through the electron relay, instead of a rectified current an alternating voltage may be used.
  • Figure 1 is a circuit diagram of a device arranged and connected according to the prior art.
  • Fig. 2 is a circuit diagram showing the arrangement and connection or a device according to one embodiment of my invention.
  • Fig. 3 is a circuit arrangement showing a preferred form of my invention, also showing diegrammatically a device combining the ionization chamber and the electron relay in a single unit.
  • Fig. 4 is a fractional and sectionized side view of the combined ionization chamber and electron relay.
  • an ionization chamber I to which is connected in parallel, through leads 60 and iii, a condenser 2.
  • the condenser 2 can be charged from a suitable D. C. current source 3, a switch 4 being provided in the negative branch 65 of the charging circuit.
  • the plate circuit of tube 6 includes a suitable current source 9, a device H to control the energlzation of the X-ray tube, and a switch 1, to open or close this circuit.
  • the device H may for example consist of a magnetic relay, the coil of which is connected in the plate circuit, and the armature of which controls the primary circuit of the high voltage transformer of the X-ray tube.
  • the circuits for such a control by device ll being obvious to one skilled in the art, have been omitted for the sake of simplicity. The same applies to the heating circuit of the oathode 5.
  • the negative electrode 62 of the ionization chamber I is connected with the grid 8 of the tube 6, whereas its positive electrode 63, together with the positive side of source 3 and of condenser 2, is connected at Bl to the plate circuit or the tube 6.
  • the condenser Before taking the X-ray exposure the condenser is charged to the proper voltage by closure of the switch I. For taking the exposure the cathode 5 is brought to its operating temperature and the switch 1 is closed, and after an intermediate closure of switch 4 the latter is opened simultaneously with the closure of the main operating switch of the X-ray tube.
  • the grid 8 being initially negatively biased with respect to the cathode 5, prevents altogether, or at least to a great extent, a current flow through the plate circuit of the tube, thus keeping the relay switch ll closed.
  • ionization in the ionization chamber establishes a discharge circuit for condenser 2 and the condenser gradually discharges through this circuit.
  • the grid bias assumes a value which allows a sufilciently high plate current to pass through the coil of relay Ii to cause the relay to open the operating circuit of the X-ray tube, thereby terminating the exposure.
  • the changes, compared to Figure 1, include two steps:
  • the first step comprises the elirnination of the connection between the grid and the charging source.
  • the condenser 2 indicated in dotted lines, instead of being charged directly, is charged through the electron tube 6.
  • A. two-position switch [2 is provided instead of the two switches 4 and l.
  • the condenser 2 is charged through the following circuit: Positive terminal of source 3, condenser 2, grid 8, cathode 5, switch l2, contact 40, back to the negative terminal of source 3.
  • the heating circuit of the cathode (not shown) being closed and the grid being positive with regard to the cathode, a current of sufiicient magnitude flows through the plate circuit to keep the relay H open.
  • the switch i2 When taking the exposure the switch i2 is moved into its right-hand position to engage contact 4
  • the condenser 2 is gradually discharged and the potential of grid 8 becomes less negative in respect to the cathode 5, until finally the plate current becomes sufficiently large to actuate the relay and interrupt the exposure.
  • the second step to improve the arrangement consists in the omission of the condenser by using a properly designed ionization chamber as the condenser.
  • the two electrodes 62 and 63 of the ionization chamber are given suflicient area and they charge up and discharge in the same manner as has been just described for condenser 2.
  • ionization chamber 13 and the electron relay I4 are connected into a single unit having, if desired, a common envelope.
  • the envelopes of these devices consist as a. rule of vitreous material, and are interconnected by a short tube [5 of insulating material, preferably of vitreous material fused to the envelopes oi devices l3 and H.
  • the electrode I! of the ionization chamber and the grid l8 of the vacuum tube are interconnected by the connection I6 which is made as short as possible and is perfectly air-tightly sealed in the connecting tube l5.
  • a common current source is assumed for the charging of the condenser and for the plate current of the tube M.
  • This source supplies rectified and smoothed current from the ordinary alternating current network 56.
  • the primary winding of a transformer 51 is connected to the network and its secondary winding i9 is in seiii) ries with a rectifier 20.
  • the rectified current so obtained is smoothed by suitable filtering means, for instance by a condenser 38 connected across the series arrangement of the rectifier 20 and the winding 19.
  • a resistor 23 acting as a potentiometer, from which the various desired potentials are tapped off.
  • of the ionization chamber I3 is connected to the positive end 45 of theresistor 23, and the electrode I1 is connected to the grid 18 of the'electron relay M by means of lead I6.
  • the end 46 of the resistor 23 is connected to the contact 66 of switch l2, whereas the contact 61 of the switch is connected to a. tap 24 of the resistance comparatively close to the negative end 45 of the resistor 23.
  • the device for the control of the X-ray tube is not placed directly in the plate circuit of the electron tube I4, but is indirectly controlled thereby.
  • the cathode 22 of the electron tube I4 is connected to the heel 39 of the switch I2, whereas its plate 21 is connected to one end 48 of a variable resistor 26, a portion of which can be short-circuited by means of sliding contact 58.
  • Tube 29 is of the type acting with an arc discharge and is not ignited until the control electrode has exceeded definite potential.
  • a current source 3% supplying an alternating or pulsating voltage, is provided in the plate cir cult of the gas-filled tube 29, which circuit also includes the coil 32 of an electromagnetic relay.
  • the armature 3d of this relay controls the energization of the X-ray tube ill, for instance by closing the primary circuit of the high tension. transformer which supplies the operating voltage for the X-ray tube and is energized from the means 12.
  • the end 49 of resistance 26 is negative compared to the end 41, the potential difference between the two depending on the voltage drop in resistance 26 and thus on the value of the plate current of tube l4.
  • the voltage drop in resistance 26 is large and renders the control electrode 30 negative with respect to the cathode 28.
  • the control electrode 30 sharply cuts off the current flow through the plate circuit of tube 29, which causes the dropping of armature 34.
  • the switch I2 is brought into its right-hand position to engage contact 66.
  • the cathode 22 is thereby rendered negative with respect to the grid l8, and the electrodes ii and 2! are charged up through the following charging circuit. From the positive end 45 of resistor 23 through electrode 2
  • the switch I2 is moved to its lefthand position contacting with contact 61. This renders the cathode 22 positive with respect to the grid l5, and whereby the current flow through the plate circuit of the tube I4 is interrupted or at least greatly reduced. This, in turn, reduces the voltage drop in the resistor 26 and the bias of control electrode 30 becomes less negative (falling below its cut-off value) and thus a current passes through the plate circuit of tube 29, which energizes coil 32 and causes, by means of armature 34, the closure of the operating circuit of the X-ray tube, which starts the exposure.
  • the X-rays passing through the object and the photographic plate strike the ionization chamber ll, causing it to be ionized, which results in a gradual equalization of the charges on the electrodes i1 and 2.
  • the grid l8 loses its negative potential and the plate current through tube l4 gradually increases until it reaches a value which causes, in resistance 26, a voltage drop which is sufiiciently large to cause control electrode 30 to assume a sufliciently negative bias to cut oil the current flow through the plate circuit of tube 29, and by means of the relay, to interrupt the exposure.
  • Fig. 4 illustrates a construction in which the ionization chamber l3 and the electron tube M are rigidly interconnected to form a single unit, the two being interconnected by means of a hollow tube 35.
  • the envelopes of chamber 13 and tube M respectively, together with the tube 35, may constitute a single vitreous body.
  • the ionization chamber is pro" vided with a neck 68 of which tube 35 may form an extension, and through which passes a re-en trant tubular portion 36 of considerable length.
  • the tube 36 supports and is partly surrounded by a hood-shaped inner electrode l1 formed of foil, whereas the electrode 2i which is arranged substantially parallel to the chamber envelope is made of thin sheet metal, although it may be formed of a foil coating of the wall or a metal deposit thereon.
  • is supported from the envelope of chamber l3 by a wire 63 which also serves as a lead thereto.
  • a portion of the envelope and the tube 36 form a very long leakage path between electrodes I! and 2!, which path is also interrupted by a metal ring 37.
  • the lead between the electrode i! of the ionization chamber and the grid E8 of the electron tube has a very high insulation so as to minimize all loss of electric charge. Therefore, the lead 55-55' is supported only at its two ends at 53 and 54.
  • the lead 5555' may form a single lead or may be separate leads interconnected at l6. As a rule, I prefer to manufacture the ionization chamber and the electron tube separately and thereafter interconnect them by fusing the tube 35 to the respective envelopes of the ionization chamber l3 and the discharge tube H4.
  • the tube 35 is preferably sealed from both the ionization chamber I3 and the relay tube I4,
  • tube Il may also be interconnected with either the ionization chamber II or with the relay tube ll. In the latter case, of course, the tube cannot be exhausted before the two are iused together.
  • the metal ring ll When the device is in operation, the metal ring ll may be connected to a negative potential, for
  • the leakage set up between the grid i8 and the ring 31 compensates for the loss of negative charge towards the cathode.
  • the charge first lost by the leakage flow between the grid and the cathode is afterwards, when the grid potential increases, regained by the leakage ilow between the ring 31 and the grid.
  • the ring 31 also prevents the condenser from being discharged along the wall of the ionization chamber.
  • a device for automatically determining the duration of irradiation comprising a vacuum discharge tube having a cathode, a plate and a grid, said grid being adapted to control the plate current 01 the tube, switching means controlled by the plate current of said tube to initiate and terminate said irradiation, an ionization chamber having a wall adapted to be subjected to said irradiation and comprising at least two electrodes,
  • one of said electrodes being connected to said grid, 0. source of direct current, a circuit including said source, said chamber, grid and cathode,
  • said source supplying through the cathode a negative charge to that chamber-electrode which is connected to the grid, means including a condenser connected in parallel with said ionization chamber to provide for a greater negative charge on said electrode, and means co-operating with said circuit to establish a predetermined decrease of the potential diflerence between the cathode and the other chamber-electrode, said negatively charged electrode discharging through the ionization chamber during a time interval which determines the duration of said irradiation.
  • a device for automatically determining the duration of irradiation comprising a vacuum discharge tube having an incandesclble cathode, a plate and a grid, said grid being adapted to control the plate current of the tube, switching means controlled by the plate current of said tube to initiate and terminate said irradiation, an ionization chamber having a wall adapted to be subjected to said irradiation and comprising at least two electrodes, one of said electrodes being connected to said grid, a source of direct current, a circuit including said source, said ionization chamber, grid and cathode, said source supplying through the cathode a negative charge to the grid-connected chamber-electrode, a plate circuit including said discharge tube, said switching means and at least a portion of said source, and means associated with said first circuit to establish a predetermined decrease oi the potential difference between the cathode and the chamber-electrode which is not connected to the grid, the negative charge of said grid-connected electrode discharging through the
  • a device for automatically determining the duration of irradiation comprising a vacuum discharge tube having a cathode, an incandesclble plate and a grid, said grid being adapted to control the plate current or the tube, switching means controlled by the plate current of said tube to initiate and terminate said irradiation, a source of direct current having a positive connection point and at least two negative connection points of diflerent potential, an ionization chamber having a wall adapted to be subjected to said irradiation and comprising two electrodes, one chamber-electrode being connected to said grid and the other chamber-electrode being connected to the positive connection point, and a changeover device to connect at will the cathode to either one of said two negative connection points.
  • a device for automatically determining the duration of irradiation comprising a vacuum discharge tube having a cathode, a plate and a grid, switching means controlled by the plate current of said tube to initiate and to terminate said irradiation, an ionization chamber having a wall adapted to be subjected to said irradiation and comprising two electrodes, a lead connecting one of said chamber-electrodes to said grid.
  • a member connecting said ionization chamber with said discharge tube and air-tightly surrounding Said lead, and means including a source oi direct current to establish a potential difference between the cathode and the other chamber electrode whereby the cathode is negative with re spect to said latter electrode and to establish a predetermined reduction of said potential diiierence.
  • a device for automatically determining the duration of irradiation comprising a vacuum dischargetube having a cathode, a plate and a grid, switching means controlled by the plate current of said tube to initiate and to terminate said irradiation, an ionization chamber having a wall adapted to be subjected to said irradiation and comprising two electrodes, a lead interconnecting one oi said chamber electrodes and said grid, an insulating tube connecting said discharge tube and said chamber, said insulating tube being exhau'sted and air-tightly enclosing said lead, and means including a source of direct current to establish a potential difference between the cathode and the other electrode whereby the cathode is negative with respect to said latter electrode and toestablish a predetermined reduction oi said potential difference.
  • An X-ray responsive ionization device comprising a sealed envelope having an insulating portion forming an electrode chamber, an insulating neck portion having a considerably smaller cross-sectional area than that of said chamber, and an insulating re-entrant portion connected to said neckportion and extending into said electrode chamber, a gaseous filling within said envelope and ionizable by X-rays, an electrode within said chamber and supported from said re-entrant portion, a second electrode within said chamber and surrounding said first electrode in spaced relationship and supported from a point on one 01 the other of said insulating portions, and a member of conductive material forming part of said neck portion and intercepting the leakage path over the envelope between said point and said re-entrant portion.
  • a device for automatically determining the duration of irradiation comprising a vacuum discharge tube having an incandesclble cathode, a plate, and a grid to control the plate current of the tube, switching means controlled by the tive charge to said grid-connected electrode, and means associated with said source to establish a predetermined decrease in the potential difference between said cathode and said second electrode, the negative charge of said grid-connected 5 electrode discharging through said chamber during a time interval which determines the duration of the irradiation.

Landscapes

  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Molecular Biology (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • X-Ray Techniques (AREA)
  • Electron Tubes For Measurement (AREA)
  • Measuring Fluid Pressure (AREA)
  • Electron Sources, Ion Sources (AREA)
US748151A 1933-11-06 1934-10-12 Device for automatic interruption of radiation Expired - Lifetime US2122222A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEM125511D DE632374C (de) 1933-11-06 1933-11-06 Einrichtung mit einem ueber das Gitter und die Kathode eines Elektronenrelais sich aufladenden und ueber eine durch Strahlung beeinflusste Ionisationskammer sich entladenden Kondensator

Publications (1)

Publication Number Publication Date
US2122222A true US2122222A (en) 1938-06-28

Family

ID=7330755

Family Applications (1)

Application Number Title Priority Date Filing Date
US748151A Expired - Lifetime US2122222A (en) 1933-11-06 1934-10-12 Device for automatic interruption of radiation

Country Status (5)

Country Link
US (1) US2122222A (nl)
DE (1) DE632374C (nl)
FR (1) FR780848A (nl)
GB (1) GB442389A (nl)
NL (1) NL40886C (nl)

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2451908A (en) * 1946-03-07 1948-10-19 Canadian Radium And Uranium Co Method and apparatus for detecting changes in dimensions
US2465377A (en) * 1938-11-24 1949-03-29 Banque Pour Entpr S Electr Gas-sensing control means with gas-discharge device
US2479271A (en) * 1946-11-21 1949-08-16 Francis R Shonka Ionization chamber circuit
US2521315A (en) * 1947-10-04 1950-09-05 Victoreen Instr Company Geiger tube
US2536991A (en) * 1945-09-18 1951-01-02 Ernest O Wollan Radiation detector
US2546500A (en) * 1947-01-22 1951-03-27 Raytheon Mfg Co Electrical circuits
US2549058A (en) * 1949-01-07 1951-04-17 James M Constable Portable radiation detector
US2574000A (en) * 1947-03-27 1951-11-06 Victoreen Instr Company Ionization and vacuum tube chamber
US2588789A (en) * 1945-05-22 1952-03-11 Atomic Energy Commission Neutron detector
US2601583A (en) * 1947-05-26 1952-06-24 Charles O Ballou Radiation measuring instrument
US2609511A (en) * 1949-10-25 1952-09-02 Jr Edward F Wright Sensitive pulse amplifier counter
US2624847A (en) * 1945-09-04 1953-01-06 William P Jesse Ballistic electrometer
US2666890A (en) * 1950-07-27 1954-01-19 Bendix Aviat Corp Apparatus for testing geiger tubes
US2692339A (en) * 1947-09-02 1954-10-19 Nat Res Dev Gamma-ray detector
US2728861A (en) * 1952-12-31 1955-12-27 Floyd M Glass Radiation pocket screamer
US2859353A (en) * 1954-06-16 1958-11-04 Cox Raymond John Circuits for current measurments
US2938197A (en) * 1954-09-14 1960-05-24 Automatic Fire Alarm Company Automatic alarm transmitter
US3011059A (en) * 1952-05-07 1961-11-28 Beckman Instruments Inc Triggering and measuring circuit for radiation integration and other purposes
US3110011A (en) * 1960-09-02 1963-11-05 Jr Benard Burson Electronic canceller for automobile turn indicators
US3483379A (en) * 1967-11-24 1969-12-09 Field Emission Corp Automatic x-ray exposure control having a detector whose response is correlated with the x-ray absorption properties of the x-ray film
US3666950A (en) * 1969-09-30 1972-05-30 Westinghouse Electric Corp Integral multi-sensor radiation detector
US5179582A (en) * 1992-04-20 1993-01-12 S&S Inficon Inc. Exposure control circuit for X-ray generation

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE762277C (de) * 1937-03-25 1954-06-08 Licentia Gmbh Vorrichtung zur Messung der Intensitaet eines Stromes langsamer Neutronen mittels einer Ionisationskammer
CH277888A (de) * 1948-07-14 1951-12-17 Walter Dr Graffunder Anordnung zur Warnung vor übernormaler radioaktiver Strahlung.
DE958041C (de) * 1952-05-20 1957-02-14 Telefunken Gmbh Wechselstromgesteuerte Relaisanordnung

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2465377A (en) * 1938-11-24 1949-03-29 Banque Pour Entpr S Electr Gas-sensing control means with gas-discharge device
US2588789A (en) * 1945-05-22 1952-03-11 Atomic Energy Commission Neutron detector
US2624847A (en) * 1945-09-04 1953-01-06 William P Jesse Ballistic electrometer
US2536991A (en) * 1945-09-18 1951-01-02 Ernest O Wollan Radiation detector
US2451908A (en) * 1946-03-07 1948-10-19 Canadian Radium And Uranium Co Method and apparatus for detecting changes in dimensions
US2479271A (en) * 1946-11-21 1949-08-16 Francis R Shonka Ionization chamber circuit
US2546500A (en) * 1947-01-22 1951-03-27 Raytheon Mfg Co Electrical circuits
US2574000A (en) * 1947-03-27 1951-11-06 Victoreen Instr Company Ionization and vacuum tube chamber
US2601583A (en) * 1947-05-26 1952-06-24 Charles O Ballou Radiation measuring instrument
US2692339A (en) * 1947-09-02 1954-10-19 Nat Res Dev Gamma-ray detector
US2521315A (en) * 1947-10-04 1950-09-05 Victoreen Instr Company Geiger tube
US2549058A (en) * 1949-01-07 1951-04-17 James M Constable Portable radiation detector
US2609511A (en) * 1949-10-25 1952-09-02 Jr Edward F Wright Sensitive pulse amplifier counter
US2666890A (en) * 1950-07-27 1954-01-19 Bendix Aviat Corp Apparatus for testing geiger tubes
US3011059A (en) * 1952-05-07 1961-11-28 Beckman Instruments Inc Triggering and measuring circuit for radiation integration and other purposes
US2728861A (en) * 1952-12-31 1955-12-27 Floyd M Glass Radiation pocket screamer
US2859353A (en) * 1954-06-16 1958-11-04 Cox Raymond John Circuits for current measurments
US2938197A (en) * 1954-09-14 1960-05-24 Automatic Fire Alarm Company Automatic alarm transmitter
US3110011A (en) * 1960-09-02 1963-11-05 Jr Benard Burson Electronic canceller for automobile turn indicators
US3483379A (en) * 1967-11-24 1969-12-09 Field Emission Corp Automatic x-ray exposure control having a detector whose response is correlated with the x-ray absorption properties of the x-ray film
US3666950A (en) * 1969-09-30 1972-05-30 Westinghouse Electric Corp Integral multi-sensor radiation detector
US5179582A (en) * 1992-04-20 1993-01-12 S&S Inficon Inc. Exposure control circuit for X-ray generation

Also Published As

Publication number Publication date
NL40886C (nl) 1937-06-15
GB442389A (en) 1936-02-07
FR780848A (fr) 1935-05-04
DE632374C (de) 1936-07-07

Similar Documents

Publication Publication Date Title
US2122222A (en) Device for automatic interruption of radiation
US2293177A (en) Electron discharge device circuits
US2292382A (en) Gaseous discharge tube system
US2044618A (en) Electrostatically controlled arc discharge device
US2264067A (en) Resistance spot welding system
US2142857A (en) Vacuum tube
US2089677A (en) Devices for tracing the movements of objects
US2883554A (en) Control means for regulating the output of x-ray apparatus
US2388812A (en) Electronic trigger method and circuit
US1938426A (en) Light sensitive apparatus
US2129383A (en) X-ray system for taking short exposure x-ray photographs
US2466749A (en) Gaseous discharge apparatus
US2083190A (en) Welding apparatus
US2466634A (en) Electrical apparatus
US2577352A (en) Device comprising a glow discharge tube
US1961717A (en) Ray intensity meter system
US2060506A (en) Electric discharge device
US1999597A (en) Electrical discharge device
US1979226A (en) Light-sensitive apparatus
US1821808A (en) Space discharge device
US1880092A (en) Electron discharge device
US2112034A (en) Electrical discharge device
US2001838A (en) Power control circuits
US2264047A (en) Resistance spot welding system
US1989132A (en) High voltage rectifier