Abstract: An arrangement for counting liquid scintillation samples on a sample plate in a liquid scintillation counter having at least one photomultiplier tube. The sample plate contains a plurality of open-bottomed wells sealed with at least one filtration membrane impregnated with a solid meltable scintillator. The arrangement includes a sample plate holder for holding and transporting the sample plate in the liquid scintillation counter. The holder includes a device to hold sample plates of different sizes and a device to enable transportation of the sample plate in the liquid scintillation counter.

Abstract: A data collection and sample handling apparatus having a frame which supports a tray for holding a plurality of test containers. The tray has a plurality of through holes and each test container is mateable within a corresponding through hole. At least one detector assembly is used to detect data from the contents or sample contained within each test container. Each detector assembly is supported by the frame. The tray is positioned on a top of the frame such that at least one test container is exposed to each detector assembly while at least one other test container is isolated from the detector assembly. A drive mechanism automatically moves the tray with respect to the detector assemblies. The drive mechanism is also used to position each test container within a corresponding detector assembly.

Abstract: A transfer device for cassettes containing radioactive samples and a cassette system in a gamma counter provided with a well-type detector. The transfer device comprises a path (61), by which cassettes (11, 12, 13) can be moved one at a time to a lifting position where sample containers can be lifted and moved to the measuring unit (50) for measuring. At the lifting position a vertical long side of the cassette (11, 12, 13) is locked in place against a vertical surface or edge (63) of the table (61) so that the distance between the center of the sample container (17) in the cassette from the vertical surface or edge of the table is substantially directly proportional to the radius of the sample container. The cassette system comprises at least two different cassettes (11, 12, 13) which are of the same length but which can take a different number of adjacently placed sample containers (17 ) of different sizes. The sample containers in each cassette are the same size.

Abstract: A method for correcting measuring values when measuring liquid scintillation samples deposited on sample plates by a photodetector which will be affected by scintillation photons from other samples in the plate in addition to the sample being measured. Said correction is done by pre-determining affection of the other samples of the plate as a function of quench level and correcting observed measuring values using this function.

Abstract: The invention relates a sample changer mechanism for radioactive samples in gamma counter for use in mass survey comprising two or more well-type detectors (56). The changer mechanism comprises a lifting device (40) for the simultaneous moving several samples (10) from the transfer unit (60) to the measuring unit (50) which includes a detector for each simultaneously measured sample.According to the invention the detectors (56) in the measuring unit (50) are on the same horizontal plane and are situated in at least two rows placed at intervals so that samples (10) need to be moved in the horizontal plane in one direction only without deviating in lateral direction i.e. the distance of the detectors from each other in the transverse direction, relatively to the transfer movement, equals the distance of the sample containers (17) from each other in the cassette (11).

Abstract: "A method for liquid scintillation counting of the radioactive nuclides of the natural decay chains of Th-232, U-238 and U-235 by detecting decay events of the short-lived members Po-212, Po-214 and Po-215 of these decay chains by the principle of delayed coincidence, characterized in that a separate pulse height spectrum is recorded for those pulses of the counting device which occur within a fixed short time interval after a preceding pulse. The successive decays cause pairs of quickly succeeding pulses to be detected; the coincidence of these pulses within a brief time interval makes it possible to distinguish the decay events from other decay events. The invention further permits simultaneous counting of different isotopes by fixing several short time intervals following a first pulse, and assigning a second pulse following the first pulse to one of several separate pulse height spectra in accordance with the length of the time interval within which the second pulse occurs.

Abstract: A system for in-situ measurement of the radioactivity of multiple samples while the samples are in a multiple-well sample tray, with a scintillator in each sample-containing well for producing light pulses in response to radiation from the respective samples. Multiple photomultiplier tubes are positioned adjacent to the sample wells containing the scintillator for simultaneously measuring the radioactivity of multiple samples with only a single photomultiplier tube sensing the scintillations from each well and converting the sensed scintillations into corresponding electrical pulses. The electrical pulses from each photomultiplier tube are processed to discriminate between pulses attributable to sample events within the wells and pulses attributable to non-sample events such as photomultipler tube noise.

Abstract: A method for performing liquid scintillation counting by the liquid scintillation counter that measures radioactive samples on a measurement support, such as a filter plate or alike, which has the sample associated therein. According to the method, the detection material, such as scintillator, is added to the measurement support before the measurement. The method according to the invention is characterized by adding detection material, such as scintillator, in melted form into the measurement support and performing the measurement after the detection material has solidified. On the filter plate is added for instance a mixture of paraffin and scintillator. One component in the detection material can be plastic scintillator.

Abstract: A multipurpose gamma counter enabling measurement of one sample at a time or alternatively two or more samples at a time and a method for sample handling in gamma measuring. The gamma counter is characterized in that the measuring unit and/or the grip unit for the sample containers are fully or partly formed of replaceable modules so that one or more necessary modular units can be fitted on the gamma counter depending on the measuring method in use at each time. The method is characterized in that, if the samples are research samples, they are measured one at a time in the detector of the research measuring chamber module and, if the samples are RIA samples, they are measured in the first place at least two at a time in the detector of the RIA measuring chamber module.

Abstract: The invention relates to a changer mechanism for individual measurement of radioactive samples in a gamma counter. The changer mechanism comprises an identifying element for identifying sample containers of different sizes and a transferring device for transferring the sample containers to the measuring unit for measuring, and back therefrom after measuring. According to the invention, the changer mechanism comprises a lifting device having a grip unit for lifting and transferring the sample from the transfer unit to the measuring unit. The grip unit is provided with grip elements for transferring samples of different sizes based on the information obtained from the identifying unit.

Abstract: A method for correction of the counting error in liquid scintillation counting in the attenuation of light passing through a sample solution is measured before or after the actual liquid scintillation counting takes place. By means of the attenuation measurement the error in the liquid scintillation counting result, caused by the colorness of the sample solution, and/or by the counting apparatus, is corrected. The apparatus has a liquid scintillation counter provided with cylinder shaped optics. A photometer is incorporated in the liquid scintillation counter. By means of the photometer, the attenuation of light passing through the sample solution is measured before or after the actual liquid scintillation counting measurement, where said attenuation is caused by the colorness of the sample solution and/or due to features of the apparatus.

Abstract: The counting error due to variations in the counting efficiency as a function of the volume of the sample is corrected. The sample is placed into a sample container which is placed into a vertically positioned cylinder shaped counting chamber. Photomultiplier tubes are disposed on the opposite ends of the counting chamber. At least two of the following spectra are measured in the coincidence counting: the sum spectrum q observed by both of the photomultiplier tubes, the spectrum q(y) observed by the upper photomultiplier tube and the spectrum q(a) observed by the lower photomultiplier tube. The counting error is corrected by the correction coefficient obtained from these spectra.

Abstract: The present invention is directed to a nuclide separation precipitator system in which noble gas nuclear fission products are introduced into a gas reservoir and generate charged daughter nuclides in the gas reservoir. A collector collects three detectable charged daughter nuclides. A detector detects the energy distributions of beta-rays and gamma-rays emitted from the daughter nuclides collected in the collector and outputs signals indicative of the detected beta-rays and gamma-rays. Three pulse height discriminators discriminate the signals output from the detector into three respective energy levels of a low energy range, a middle energy range, and a high energy range. A first order simultaneous equation of three unknowns obtained by utilizing a fact that counting ratios of the three energy ranges vary for each daughter nuclide is then solved.

Abstract: Apparatus for performing and measuring chemical reactions includes a reaction test apparatus having reaction wells wherein reactants are controllably mixed, and exposure apparatus which receives and positions the reaction test apparatus adjacent a photographic film. Each of the reaction wells includes at least two reaction cups, arranged one above the other. The uppermost reaction cups have orifices in the bottoms, so that liquid can be mixed and reacted in the uppermost cup, and then controllably transferred to the lower cup to be mixed with additional reactants. In a preferred embodiment, the reaction cups are supported in plates that are structurally integrated with the cups, and are superimposed to make a test block. The test block is retained in the exposure apparatus, and liquid is forced from the upper cup to the lower cup by application of pressure to the top of the upper cup.

Abstract: A device for simultaneously measuring the level of particle and quantum radiation of a plurality of samples which includes a microplate having a plurality of wells for accommodating the plurality of samples. A plurality of light conductors, at least one for each well, is positioned to receive light from each well and forward it to a photodetector. When luminescence is determined, each well has only one conductor associated therewith and when liquid scintillation is determined, each well has two light conductors associated therewith.

Abstract: Liquid scintillation counter includes a memory having stored spectra of known counting efficiencies and known levels of quench, for the isotopes to be meansured. A device extracts from the spectra, using the determined quench level value for each of the N isotopes, a reference spectrum representing a pure isotope spectrum at the determined quench level. A device determines for each extracted reference spectrum a factor by which the extracted reference spectrum is to be multiplied in order to fit the sum of the multiplied reference spectra to the sample spectrum. Each factor is directly related to the amount of each isotope in the sample.

Abstract: Liquid scintillation counter includes a memory having stored spectra of known counting efficiencies and known levels of quench, for isotopes to be measured. A device extracts from the spectra, by using the determined quench level value for each of the N isotopes, a reference spectrum representing a pure isotope spectrum at the predicted quench level. A device determines for each extracted reference spectrum a factor by which the extracted reference spectrum is to be multiplied in order to fit the sum of the multiplied reference spectra to the sample spectrum. Each factor is directly related to the amount of each isotope in the sample. A device computes a goodness-of-fit value and predicts a new value for the quench level based on this goodness-of-fit value. A method in liquid scintillation counter includes predicting a first value of the quench level of the scintillation sample.

Abstract: To produce a quench calibration function for a liquid scintillation counter having stored a basic correlation between a quantity to be quench calibrated and a quench index, the value of the quantity to be quench calibrated and the value of the quench index for at least one reference sample is measured by measuring means from said basic correlation, the value of the quantity to be quench calibrated for the measured value of the quench index for each reference sample is evaluated by evaluating means. Then the difference or ratio between the measured and the calculated values of the quantity to be quench calibrated for each reference sample is calculated by calculating means, whereupon said calculated difference or ratio as a function of quench index is approximated by approximating means, and said basic correlation and said function of quench of quench index are combined into the quench calibration function by combining means.

Abstract: For simultaneously measuring the radioactivity of multiple samples arranged in a predetermined array of x rows and y columns, a fixed array of radiation counters arranged in the same array of x rows and y columns so that one of the counters is aligned with each of the multiple samples. Each of the counters has a pair of spaced electrodes; an electrical voltage source connected to the electrodes of all the counters for applying the same voltage across the electrodes of each of the radiation counters in the array; and sensing means connected to the electrodes of each of the radiation counters for independently detecting pulses of electrical current produced by ionization of the gas between the respective pairs of electrodes of each of the radiation counters. For measuring low-energy radiation, the radiation counters are windowless, a flow of ionizable gas is supplied to the counters, and the same flow rate of the ionizable gas is maintained through each of the radiation counters in the array.

Abstract: A device for detecting ionizing radiation emanating from a plurality of samples, said device comprising: a receptacle having a planar surface and provided with a plurality of recesses each for holding a respective sample, each said recess being open at said surface; a cover member having at least one planar electrically conductive member provided with openings, said conductive member being spaced from said receptacle and being disposed parallel to said planar surface; and a voltage source connected to place said electrically conductive member at a potential which is positive relative to the potential of said planar surface.

Abstract: An arrangement for improving the counting of liquid scintillation samples including a plurality of separate sample wells, a plate holder surrounding the sides of each sample well so that each plate holder forms an optically separate compartment for each sample well, at least one photomultiplier tube adjacent each sample well, and a coating of light reflective or light scattering material on the inner surfaces of said plate holders.

Abstract: A plate-shaped collimator with a plurality of through-bores for increasing locality-sensitivity during measurement of the radiation from a radioactive substance, by means of a detector disposed adjacent the collimator, wherein the collimator is provided with an insulting core having two opposed major surfaces, two electrically conductive layers each disposed on a respective collimator surface, and a source connected for applying a voltage for creating, between the conductive layers, an electrical field which acts on charged particles emanating from the radioactive substance to exert on these particles a force having a main component which is directed towards the detector in a direction substantially perpendicular to the conductive layers.

Abstract: The invention relates to a method and an apparatus for measuring the radioactivity of samples that are arranged in the wells of a microtitre plate and in which the radio-activity is solid-bound, for example cell-bound, or is in the form of a protein precipitate, wherein samples suspended, dissolved or mixed in liquids are first separated from the liquids and then their liquid supernatant is removed by suction. The invention comprises connecting the bases (4) of the wells of the microtitre plate to one another and then separating them from the microtitre plate or the well walls in such a manner that they remain connected, and subsequently measuring the samples they carry in succession, in groups or simultaneously over the entire grid.

Abstract: An apparatus for counting liquid scintillation samples which includes a sample plate containing a plurality of cup-shaped sample wells, a photomultiplier assembly over the tops of said cup-shaped sample wells, a photomultiplier assembly beneath the bottoms of said cup-shaped sample wells and light reflective tubes extending upwardly from said lower photomultiplier assembly and surrounding each cup-shaped sample well.

Abstract: Determining whether a liquid scintillation sample is single- or multi-phase includes transforming all or a portion of a Compton Spectrum of data into different namely integrated, geometric space. A predetermined parameter in the selected geometric space, indicative of the phase content of the sample is selected, and compared with the data in the different geometric space. This provides a determination of the phase content of the sample. The linearity of the data indicates the phase content.

Abstract: A stepping apparatus uses two gate elements driven by solenoid actuators to block a detector string as it is advanced to a gamma counter so that the string can be advanced at a controlled rate, one ball at a time. The gate elements each have two interconnected passages, one of which permits passage of the entire detector string, while the other permits passage of the cable but not the balls.

Abstract: Monitoring and measuring colored samples by the techniques of liquid scintillation counting employs the relationship of absorbance and counting efficiency. A determination of whether color quench correction is required is made. Should a color monitor detect a color intensity which requires color correction, then efficiency correction is performed here. Both the color monitor and the color correction of efficiency are incorporated into a liquid scintillation counter which performs color monitoring, measurement and correction automatically.

Abstract: A carrier for at least on beta-particle-emitting sample to be measured in a scintillation counter comprises a sorption sheet on which the sample is to be deposited, a transparent bag within which the sorption sheet with the sample is to be contained, and a scintillant to be contacted with the sample within said bag. According to the invention the scintillant is a meltable solid scintillant which is coated onto at least part of the sorption sheet and/or the inside of the transparent bag, and which is to be melted to envelop and permeate the sample before measurement thereof.

Abstract: In a method of producing a carrier for a plurality of radioactive samples to be monitored in a liquid scintillation counter,wells are provided in a rigid plate (1) of a photon attenuating material in that holes disposed in a matrix configuration are covered from one side of the plate (1) by a first photon permeable foil (2),sample carrying cut-outs (3) from a sorption sheet on which samples have been deposited are placed in said wallsa scintillation fluid is added to the wells, andthe wells are sealed by a second permeable foil (4) to keep the cut-outs (3) and the scintillation fluid within the respective wells.

Abstract: A method for determining the distribution of a radioactive material in a medium is provided which comprises the steps of: (a) providing a plurality of radiation detectors at a set of predetermined locations, each of said detectors producing an electrical output indicative of the amount of radioactive material in the vicinity of the detector; (b) moving the medium containing the radioactive material and the plurality of radiation detectors relative to one another so as to position the medium relative to the detectors at each of a set of predetermined positions; and (c) recording the electrical output of each of the detectors at each of the predetermined positions. Apparatus for practicing the method is also provided.

Abstract: An improved beta activity counter is disclosed which provides for counting plural, preferably even numbers of, samples simultaneously, while allowing automated handling of sample vial racks which are different widths are multiples of the number of simultaneous testing cells. The number of indexing steps needed per rack are adjusted automatically according to the number of vials that each rack will hold. Quench counting of adjacent samples simultaneously via use of one external source is also provided.

Abstract: In a liquid scintillation counter the light output from a liquid scintillation sample containing radioactive isotopes of unknown activity is measured by means of a detector. A pulse height analyzer having discriminators that are combined to define pulse height windows, is connected to the detector for measuring and temporarily storing count rates for each of the windows. Moreover, there are means for determining a value for the quench level of the sample. According to the invention the number of pulse height windows is at least N+1, when the number of isotopes is N,N being .gtoreq.2. There are memory means for storing for each of said windows representations of counting intensities determined by measuring calibration samples of each isotope at different levels of quench.

Abstract: This invention is a technique to determine radioactivity of low energy beta emitters using liquid scintillator. Corrections for regression equations which represent the relationship between counting efficiency of a standard and counting rate of a sample make it possible to obtain the radioactivity of the low energy beta emitters. It is very difficult for the emitters to be measured with the conventional efficiency tracing technique.

Abstract: An efficiency extrapolation method is used in liquid scintillation counting for determining activity in an unknown sample. A dynamic and automatic determination of the range of the pulse height spectrum is used to permit a counting measurement in highly quenched samples, and with isotopes having low energy end points. A selected linear regression equation is extrapolated to provide the determination within a predetermined error established by a least squares condition.

Abstract: A liquid scintillation counter system utilizes multiplexing to monitor scintillation events in a continuously flowing effluent, using relatively few sensors, such as photomultiplier tubes, each such photomultiplier tube, in a specific embodiment, receiving light generated by scintillation events at a plurality of predetermined monitoring points along the flow path of the effluent. Each monitoring point, is coupled by means of light guides to at least two of the photomultiplier tubes. Some background noise is eliminated by use of discriminators which establish a predetermined threshold level for the magnitude of the outputs of the photomultiplier tube, above which the pulses are countable. Coincident circuitry is used to determine the presence of a scintillation event, and thereby issue a coincidence pulse which is counted. In accordance with the invention, n photomultiplier tubes can be used to monitor (n/2)(n-1) monitoring points along the flow path.

Abstract: Method for reducing quenching effects in analytical luminescence measurements. Two embodiments of the present invention are described which relate to a form of time resolution based on the amplitudes and phase shifts of modulated emission signals. In the first embodiment, the measured modulated emission signal is substantially independent of sample quenching at sufficiently high frequenices. In the second embodiment, the modulated amplitude and the phase shift between the emission signal and the excitation source are simultaneously measured. Using either method, the observed modulated amplitude may reduced to tis unquenched value.

Abstract: In place of the conventional photographic DNA sequencing gel method, the present disclosure proposes directly scanning the radio labeled DNA fragments of successive information tracks on the gel to produce an on-line contemporaneous display. In this way, the scanning and/or display may be modified during the progress of the scanning operation, for example to emphasize the development of selected portions of the gel which exhibit relatively faint radioactivity. The scanning operation preferably takes place by a constant speed rotation of the gel and an arcuate scanning of a radioactive detector head with the schedule of angular velocity of the detector varying to maintain a relatively constant relative scanning velocity between the detector head and successive points on the surface of the gel.

Abstract: For the determination of filterable pollutants in gases there is a filter sc, which is located on a horizontal, compact rotary plate, which is moved over a suction head, whose suction lips interact with corresponding holes or borings in the rotary plate. The suction head is pushed upon from underneath by action of a universal-joint spring bearing against the plane-parallel rotary plate. Preferably, the rotary plate is rotated each time in steps at determined cycle times, specifically according to a program, by a determined number of collection spaces with "phase-shifted" multiple rotations of the plate, until the filter surface is completely used up. Instead of a filter disc, absorber material can also be used for radioactivity monitoring with a forward motion cycle of 1 to 2 days.

Abstract: A radiation detection apparatus designed to permit the use of samples of various types and sizes. The apparatus comprises a sample housing fixed to the apparatus and defining a fixed opening adjacent a radiation detection element. Sample containers and sample holders are removably supportable in the sample housing. Sample vials and dry sample containers of different sizes are positionable in said sample holders to provide a sample at a fixed distance from the detection element. Also, a dry sample container and a filter sample holding device usable with the apparatus, are disclosed.

Abstract: A baggage inspection system has a conveyor path disposed between an X-ray source, which genertes an X-ray beam, and a radiation detector for detecting radiation passing through articles on the conveyor path. The conveyor path is formed by two surfaces disposed at a right angle relative to each other, with the right angle being inclined relative to the horizontal so that articles on the conveyor path are forced by gravity to lie against one of the surfaces. At least one of the surfaces is a moveable surface, and the other surface may also be a moveable surface, or a roller surface or a plate against which the articles slide. The radiation detector may be an angled detector row so as to encompass substantially all of the radiation beam within its field of view.

Abstract: A liquid scintillation counter system utilizes multiplexing to achieve monitoring of a plurality of scintillation samples using relatively few sensors, such as photomultiplier tubes, each such photomultiplier tube, in a specific embodiment, receiving light generated by scintillation events in a plurality of the scintillation samples. Each scintillation sample, which may be contained in a vial, is coupled by means of light guides to at least two of the photomultipler tube. Some background noise is eliminated by use of discriminators which establish a predetermined threshold level for the magnitude of the outputs of the photomultiplier tube, above which the pulses are countable. Coincident circuitry is used to determine the presence of a scintillation event, and thereby issue a coincidence pulse which is counted. In accordance with the invention, n photomultiplier tubes can be used to monitor (n/2)(n-1) samples.

Abstract: This invention is concerned with the automatization of the efficiency tracing method in liquid scintillation measurement. In a conventional efficiency tracing method, the radioactivity has been determined by changing in turn several kinds of measurement conditions and by manually drawing a graph. In order to overcome these inconveniences, the present invention provides a measuring method and apparatus therefore in which the measurement region of a pulse height analyzer which is determined by a lower level and an upper level is fixed in a liquid scintillation counter, a data group obtained by measuring the counting efficiency of a standard sample and the counting rate of a subject sample is automatically determined from the regression equation. Thus the efficiency tracing method has become extremely convenient and its utility has been significantly improved.

Abstract: Liquid scintillation vials are disclosed formed from polyethylene or polypropylene and fluorinated on at least the inner surface. The advantageous physical properties and disposability of polyethylene or polypropylene are retained, while reducing permeation of organic solvents of the scintillation cocktail into or through the walls. Therefore problems of vial swelling, resulting in jamming of scintillation counters, are avoided.

Abstract: Apparatus and a method useful for identifying and verifying which radionuclide is present in a test sample for use in a liquid scintillation counter is disclosed. The invention is directed to measuring a quench-indicating parameter of the sample and an external source quench-indicating parameter. The measured values are compared to known radionuclide equations to determine if an identifying fit exists. If the measured values are determined to satisfy, one of the known radionuclide equations, then the identity of a radionuclide is established. In a multilabel sample the measured values may be used to identify the radionuclide having the highest end point maximum energy.

Abstract: In a sorption sheet (1) for sorbing a plurality of discrete samples that simultaneously emit photons or beta particles, the emission thereof to be individually monitored, barriers (2) of a photon and/or beta particle attenuating material extend through at least a portion of the thickness of the sheet (1) which is known per se, to prevent cross-talk between the samples when monitored. The barriers are produced by soaking a liquid photon and/or beta particle attenuating material in a pattern of lines through at least a portion of the thickness of the sheet, whereupon that material is dried and/or cured.

Abstract: A TLD card reader comprising infeed and outfeed carousels for sequentially indexing cartridge holders for stacks of TLD cards to infeed and outfeed stations, and a shuttle transport for sequentially transferring TLD cards from the infeed station to a card read station and then to the outfeed station. At the read station plural photomultiplier tubes are mounted in opposition to respective hot fingers which are independently adjustable along three axes as well as independently biased for engagement with respective TL elements in a TLD card. For photomultiplier tube calibration a shuttle assembly is operable to move reference lights into the path of the shuttle transport for alignment with respective photomultiplier tubes. A light seal of star-like cross-section also is provided to seal the shuttle passageway at the read station.

Abstract: A method for measuring the radioactivity in eluates from liquid chromatography columns in which a portion of the eluate stream is split off and mixed with a scintillation fluid in a timed sequence wherein the volume of eluate and the volume of scintillation cocktail are quantitatively and reproduceably controlled. An apparatus for the practice of this method comprising a two-position valve on the affluent stream, a two-position valve on a pumped closed loop of scintillation cocktail a means for simultaneously setting the position of each valve and a mixing chamber discharging to a scintillation counter is also described. By the practice of this method, it is possible to determine the radioactivity of the eluate as well as to preserve a sample of the eluate for further analysis.

Abstract: Method to determine the degree of chemical quench and the degree of color quench in liquid scintillation samples in order to find the correct counting efficiency for the samples. Scintillation pulses produced by the liquid scintillation solution as a result of an isotopic decay or in response to radiation from an external .gamma.-radiating source, are counted in a counter comprising two photodetectors working in coincidence, means for determining the value of one quench parameter dependent on the overall level of quench in the solution, and means for determining the value of another quench parameter predominantly dependent on the level of color quench in the solution. The counting efficiency for the sample can be determined on the basis of these two quench parameters.

Abstract: An infrared spectroscopy instrument includes a housing having a sample chamber which is sized and shaped to accommodate the body of an automatic feeding slide projector of the type commonly utilized with standard photographic slide transparencies. The infrared beam is reflected by a system of mirrors into a beam path which extends through a portion of the slide projector mechanism ordinarily occupied by the projector lamp and optics, which have been removed. Samples are held in special sample holders adapted in size and shape to fit the compartments utilized in the slide magazine of the projector. These sample holders are indexed one at a time under the control of the instrument into a viewing position in the path of the infrared beam, and the beam passed through the sample is then collected and focused onto a detector.

Abstract: A method and apparatus for indicating quench associated with a liquid scintillation solution wherein the solution includes a sample, a solvent and a solute. The method includes exposing the solution to flashes of light, detecting a pulse height spectrum for scintillations produced in the solution in response to the light flashes, determining a unique point on such pulse height spectrum, and relating the unique point to a corresponding pulse height value, such pulse height value providing an indication of quench associated with the solution. The wavelength of light preferably excites essentially only the solvent and the light flash intensity and duration is such that the pulse height spectrum produced in response to the light flashes does not overlap a pulse height spectrum for the sample in the solution. An attribute of the shape of the light pulse height spectrum may be examined to provide an indication of the homogeneous or non-homogeneous nature of the quench present in the solution.