Abstract: A flow cell for liquid scintillation counting having a spool wound with a length of light transparent tubing provides a variable volume of sample solution for analysis by selectively winding the spool with a select length of tubing, thus controlling sensitivity of anaysis and maintaining resolution of separated constituents in the sample. The flow cell comprises a spool rotatably held within a framework and which may be covered with a transparent material.

Abstract: An apparatus for a selective on-line determination of aqueous tritium concentration is disclosed. A moist air stream of the liquid solution being analyzed is passed through a permeation dryer where the tritium and moisture and selectively removed to a purge air stream. The purge air stream is then analyzed for tritium concentration, humidity, and temperature, which allows computation of liquid tritium concentration.

Abstract: A low-level liquid scintillation measurement system for counting sample optical events resulting from the radioactive decay of a constituent of a sample to be measured while reducing the counting of background optical events which are optical events produced by background radiation and which create electrical pulses other than pulses representing a sample optical event.

Abstract: A sealed container for either wet or dry radioactive samples to be counted by an associated counter. The container includes a carrier having an aperture formed therethrough. A window is connected to one side of the carrier and defines a cavity with the carrier. The cavity is accessible via at least one aperture in the carrier. A tab is removably attached to another side of the carrier for sealing the aperture.

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: 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: A device for continuously and accurately measuring the number of bacteria present in superpure water such as may be used in the manufacture of semiconductor devices and the like. A sample flow of the superpure water is passed through a generally rectangular measuring flow path having a small thickness and large width. A reagent is added to the flow in the measuring flow path of a type which reacts with bacteria to produce products which fluoresce upon application of an exciting light beam. The light produced by such fluorescence is detected and the detection output converted to a signal indicative of the number of bacteria present in the sample flow.

Abstract: A dry solid scintillator counting composition for the detection of radiative substances in a liquid comprises a mixture of fluor particles and a binder bonding the particles into a coherent structure, the weight amount of the fluor being sufficiently greater than the weight amount of the binder to render the structure sufficiently porous between the disposed particles of fluor to provide transport of a saturating amount of liquid throughout at least 50% of the volume of the composition.

Abstract: A liquid scintillation counter comprises a detector with a measuring chamber disposed on a horizontal plate having two holes and a device for delivering a test specimen to the measuring chamber, which is arranged under the plate and has a screw pair with a lead screw and a nut, guides with vertical slots to ensure progressive upward and downward movement of the nut and a shutter installed below at the outlet of the vertical slot. The nut mounts a receiving assembly secured so that it is found precisely within any hole in the plate after the nut is turned and lifted. Said nut has at least one roller secured on its butt end and interacting with the vertical slot, said roller cooperating with the shutter at the outlet of said vertical slot.

Abstract: Apparatus and method for measuring the density of sperm in a sample and for calculating the magnitude of dose required for artificial insemination. An optical assembly with light source, specimen holder and photodetector providing a signal to an amplifier the output of which is proportional to absorbance of the sample. A signal selection system utilizes three parallel signal channels with each having a different correction factor for matching the absorbance signal to actual density count, and including means for selecting the appropriate signal channel as a function of signal amplitude, with the output when calibrated providing the direct reading of the sperm density. Knowing the number of sperm cells desired per insemination and the percent motility of the sample sperm, the required dose is calculated as a function of the density count.

Abstract: Apparatus and a method for determining a quench-indicating parameter of a test sample utilizing a liquid scintillation counter are disclosed. The number of counts in a spectrum resulting from subtraction of a spectrum generated without an external source of radiation from a spectrum generated with an external source of radiation is utilized. The total number of counts is cumulatively summed from a higher energy level to a lower energy level and a curve representing this sum is generated. A portion of this curve is fitted with a function such as a straight line and the intersection of that function with the zero count axis is the intersection energy level which is an indication of the measure of quench of the test sample.

Abstract: Apparatus and a regionless method of ascertaining the activity of each radionuclide in a dual-label sample. A set of correlation curves is generated utilizing quench standards for both a low energy radionuclide and a high energy radionuclide. A test sample was then counted and the quench-indicating parameters for the test sample are compared with the quench-indicating parameters of the correlation curves to determine the appropriate contribution of each radionuclide to the overall energy spectra of the test sample. From this comparison the overall count rate for the test sample may be allocated between a low energy radionuclide and a high energy radionuclide. By dividing the count rates by efficiencies determined from another set of correlation curves the actual disintegration per minute (DPM) rate for each radionuclide may be ascertained.

Abstract: A liquid, homogeneous mixture for use in the LSC (Liquid Scintillation Counting) analysis technique, comprising a scintillation liquid, a scintillator and a surfactant, wherein the surfactant includes one or more phosphoric acid esters having formula 1 and/or formula 2 of the sheet of formulae, in which R', R" and R'" represent an organic group, which phosphor acid esters are neutralized to a pH, at which the neutralization product comprises a mono- and/or diphosphate with an alkaline material having a pK.sub.a of at least 5, and in which of the organic phosphoric acid esters having formula 1, R" and R'" may be the same or different.

Abstract: An instrument for measuring levels of concentration of tritium and tritium oxides in environmental air includes a scintillation detector, such as a photomultiplier, and a controlled device for exposing scintillators to the detector in succession. Air being monitored is passed over the scintillators. A thermoelectric device is used to cool and warm one of the scintillators for condensing air moisture onto its surface and for evaporating moisture from it, the count rate being measured in both instances. The other scintillator is a reference scintillator, the count rate from which is also measured, and a measurement is taken with neither of the scintillators exposed to the scintillation detector. The concentration levels of tritium and tritium oxides are computed from the set of measurements.

Abstract: Measuring arrangement for determining the concentration of gaseous radioiodine in a carrier gas, composed of a mass of sorption agent for separating the gaseous radioiodine from the carrier gas and for accumulating the separated radioiodine, with a part of the mass of sorption agent being located in a measuring region, a conduit for conducting the carrier gas to the sorption agent and provided with at least one outlet via which carrier gas can flow into the measuring region containing sorption agent, and a radiation detector disposed for detecting radiation emanating from the measuring region, with the sorption agent being movable relative to the conduit for bringing different portions of the mass of sorption material into the measuring region.

Abstract: An apparatus for measuring the concentration of radioactivity in a radioactive fluid discharged from a nuclear power plant. The apparatus comprises a radioactivity concentration measurement pipe arranged to extend vertically, fluid supplying means for supplying the fluid into the measurement pipe in such a manner that the fluid flows down through the measurement pipe along the axis of the measurement pipe without contacting the inner surface of the latter, radioactivity concentration measuring means disposed at the outside of the measurement pipe for measuring the radioactivity concentration in the fluid flowing in the measurement pipe, and means for discharging the radioactive fluid to the outside of the measurement pipe. The apparatus further comprises a gas supply pipe opening at its one end to the atmosphere and communicated at its other end with the inside of the measurement pipe, and a check valve disposed in the gas supply pipe and operated at a pressure higher than the atmospheric pressure.

Abstract: Method and apparatus for counting nuclear scintillations of a specimen containing tritium. A simple system using a single photomultiplier tube and suitable circuitry segregates the pulses which are emitted from a scintillator due on interaction with a nuclear particle from the pulses attributable to random noise. The system is operable with many scintillation materials as long as the characteristic output from the scintillator is long relative to the duration of a random noise pulse. The preferred embodiment of this radiation assay instrument includes a solid scintillator, a photomultiplier tube whose output is split among a two-path circuit containing a first path for providing an integrated pulse signal as input to a pulse height analyzer and a second path which discriminates based on the number of component pulses in the signal to provide an enable signal to the pulse height analyzer.

Abstract: A portable photo chamber for photographically recording the extent of a chemical reaction such as in an immunological test, wherein a substrate emitting radiation such as gamma radiation is supported in facing contact with a film and with intensifying means, so that exposure time is reduced as a result of emission of further radiation such as a visible light from the intensifying means and its recording on the film. The photo chamber includes retaining means for supporting the substrate, which itself is preferably enclosed in a container such as a pipette, and translating means for moving the substrate into closely facing relationship to the film and also to a spaced-apart position within the chamber. In a preferred embodiment, the photo chamber utilizes an instant photographic system with film processing means attached to the chamber, so that the photo chamber is both portable and self-contained for use in remote locations.

Abstract: A method and apparatus for detecting .alpha.-rays present in a specified energy range includes a chamber in which is located a filter, an .alpha.detector and a measuring space which is kept at less than 40% of normal atmospheric pressure. The reduced measuring space pressure in turn reduces energy loss of the .alpha.-particles as they travel from the filter to the detector, thereby permitting a high degree of differentiability of the .alpha.-particles according to their energy levels while at the same time providing a large enough sample of .alpha.-particles for .alpha.-activity measurement. Sufficient collimation of the .alpha.-rays is effectuated by limiting the linear distance across the detector receiving surface as compared with the distance between the detector and filter receiving surfaces. The collimation is further improved by tapering conically the inside surface of the chamber toward the detector, and by disposing the average aperture angle of the surface elements of the filter between 90.degree.

Abstract: For hot hydrocarbon liquids and slurries containing a vapor portion derived from a hydrogenation process, the vapor portion is separated from the liquid portion within a separation zone by providing a liquid vortex flow pattern having a gas core. The vapor is withdrawn from the vortex core through an inwardly-extending conduit, and the remaining rotating liquid portion is passed to below the vortex. If catalyst particles are also contained in the hot hydrocarbon liquid, such as in a coal or oil hydrogenation reaction effluent liquid at elevated temperature and pressure conditions, such catalysts can be conveniently separated from a product liquid stream and returned to the reaction zone along with the recycled liquid. A clean liquid stream is withdrawn from the recycled liquid for further processing. If desired, the phase separation zone utilizing a liquid vortex can be provided within the catalytic reaction zone.

Abstract: A relatively small diameter, relatively deep hole is made in the ground and a sampler tube is inserted therein. An acetate sleeve is detachably inserted into a chamber on the upper end of the sampling tube and the sampler is left for at least sixteen hours and preferably longer in order to permit radon gas to migrate up the tube. Daughter products of radon deposit on the acetate film which is then placed in a scintillation cell attached to the counting chamber of a scintillation counter, which counts the alpha emissions of the daughter products thereby permitting the amount of radon gas to be calculated. This method reduces considerably any contamination of the scintillation counting chamber so that cleansing is not necessary thus permitting a much higher level of productivity. The system is also totally insensitive to thoron so that no correction for thoron signals is required.

Abstract: A portable radiation dosimeter unit for continuously measuring exposure to radioactive decay products in ambient air. The unit is constructed as a unitary assembly suitable for mounting on a portable battery casing, the assembly housing a constant flow air pump for maintaining a constant flow of air through a filter, a detection unit and electronic circuitry connected to the detection unit for processing, counting and storing pulses generated by the detection of radioactive particles from decay products entrapped by the filter. The filter is readily replaceable, and in use is clamped in position by a clamp assembly pivotally mounted on a front wall of the unit, the clamp assembly providing an internal air passage forming part of the air flow path and positioned to receive the air which is drawn through the filter.

Abstract: Method for testing a liquid scintillation sample to determine whether it is separated into different phases. Scintillations emitted by the sample in response to radiation from an external radiation source are analyzed. If the distribution of the intensities of the scintillations has a characteristic indicating it is the superposition of the intensity distributions of scintillations emitted by two or more distinct phases, then the sample is adjudged to be separated into different phases.

Abstract: The invention relates to a liquid scintillation spectrometry process and apparatus permitting the analysis of samples having a fluorescence efficiency quenching comprising chromatic quenching and chemical quenching. According to the invention, an external standard ionizing radiation source is used which is associated with a collimating means permitting the irradiation of the sample to be restricted to a small area. According to a first variant, two separate measurements are carried out on fluorescence radiations having different optical paths. These two measurements make it possible to determine a coefficient which represents the ratio between the chromatic quenching and the chemical quenching. In a second variant, the irradiation area is selected in such a way that the overall quenching is no longer dependent on this ratio.

Abstract: A fluorescent composition useful in thin-layer chromatography comprises an inert porous particle having a fluorescent material fixedly attached by covalent chemical bonding to the surface thereof. A process for synthesizing this fluorescent composition is disclosed. A method for detecting the radioactivity of a radioactive species using a cell packed with such a fluorescent composition is also disclosed.

Abstract: In an instrument for measuring radioactivity, the total measuring time for each sample is optimized by considering the maximum acceptable total counting error as well as the count rate. Each sample is counted for a period of time that is considerably shorter than the required measuring time but long enough to estimate the average pulse frequency, then the measuring time is determined as a function of the estimated pulse frequency and of the experimental error as determined by the channels ratio method.

Abstract: Proposed is a device for radiochromatographic analysis of mixtures of substances containing components tagged by radioactive isotopes, such as soft .beta.-isotopes comprising a chromatographic column, a detector of nuclear radiation and a chromatographic detector connected in series along the flow of the substance being analyzed. The detector of nuclear radiation is provided with a cell made as a tube with a scintillator applied onto its inner surface in the form of a solid layer. The tube is provided with movable means for sequentialy cooling and heating the same and a light detector which is movable along the length of the tube. In operation, upon introduction of the portion of the mixture being analyzed into the column, with the heater interacting with the tube, the heater and cooler are moved so that by the time the last component of the mixture exits from the column, the cooler is in interacting relationship with the tube whereby the components of the mixture are frozen.

Abstract: Apparatus for the detection and analysis of particulate material carried in a fluid stream comprising a sampling device through which the fluid stream may be passed, said sampling device incorporating means for arresting and carrying an accumulation of particles restrained from flow in the fluid stream, means for directing ultra-violet radiation onto the sampling device at a location where the accumulation of particles results, and means whereby optical radiation analysis may be performed of the radiation emitted by the accumulation of particles consequent upon their excitation by the ultra-violet radiation means.

Abstract: Apparatus for light flux attenuation particularly for additional quenching of scintillations in the determination of radionuclide activity comprising a body provided with a counting chamber containing a counting vial which is optically coupled with photomultipliers and between which is disposed a cylindrical spring. The opposite ends of the spring are secured in the body and the spring extends in surrounding relation with a rotatable bush mounted in the body. The bush is provided with a ring having a hole through which the cylindrical spring passes such that the ring divides the spring into a first portion surrounding the counting vial and a second portion surrounding the rotatable bush.

Abstract: An arrangement for continuously measuring the radioactivity of solutions of matters in a homogeneous mixture with a liquid scintillator, comprising two measuring chambers and a two-way tap valve connecting, in its first position, the first measuring chamber with the mixing device, and the second measuring chamber with a multi-channel pump, and in its second position, the first measuring chamber with the multi-channel pump, and the second measuring chamber with the mixing device.

Abstract: The invention relates to a liquid scintillation spectrometry process and apparatus permitting the analysis of samples having a quenching of the fluorescent efficiency resulting both from a color quenching and a chemical quenching. The invention makes it possible to measure a parameter B which gives the respective contributions of the two quenching types. According to the invention, parameter B is obtained in the following manner. A scintillation radiation produced by a standard fluorescent source placed in the vicinity of the sample to be measured is passed through the latter. This source comprises, for example, a solid scintillator exposed to an alpha or beta radiation source. The scintillation emitted by the standard source supplies an amplitude spectrum which is measured. One of the significant characteristics of this spectrum is determined, for example, the ratio of the counting rates in two different channels. This ratio gives parameter B.

Abstract: A method for determining the working level exposure to airborne radioactive material by measuring the beta count per unit time. The gas radon-222 gives off three short lived daughter products commonly designated as RaA, RaB and RaC. Air, within the environment whose level is to be measured, is pumped through an opened face filter and screen assembly forming part of a detector holder mount. Radioactive particulate matter, consisting of radon-222 daughter products is collected on the filter. Thereafter, beta particles generated by the radioactive decay of the daughter products impinge upon a Geiger-Mueller tube which detects the beta particle activity per unit time. A pulse integrating system counts the detected beta particles. Based on prior experimentally calibrated results, the total count of beta particles is converted to a working level exposure.

Abstract: An apparatus for irradiating a flowing material with an electron beam includes an electron beam accelerating device having an electron beam emitter; an irradiation device having an inclined irradiation tray arranged underneath the electron beam emitter and determining a flowpath for the material to be irradiated; and a material feeding arrangement for introducing the material onto the inclined irradiation tray. The material feeding arrangement comprises a riser vessel having an upper portion, a bottom portion and an overflow edge situated at the upper portion and adjoining the irradiation tray upstream thereof as viewed in the direction of material flow and at least one diffuser communicating with the bottom portion of the riser vessel for introducing the material thereinto.

Abstract: A method of analysis in which a radioactive substance is distributed in a liquid phase and a solid particle phase and radiation from one phase is measured while attenuating the radiation from the other phase, the radiation from said other phase being shielded according to the invention by virtue of the fact that said phase is mixed with and/or contains a radiation-absorbing material in such a quantity and concentration that the dominant portion of the radiation from this phase will be absorbed.

Abstract: A scintillation cell having cylindrical symmetry, thickened walls, and components with different coefficients of thermal expansion. A pliable epoxy bonds the components together and accommodates their varying expansions during temperature changes. The glass through which passes the luminescence produced by the radioactive particles to the photomultiplier tube sits inside of the cylindrical metal tube to which it attaches. This recessed configuration protects the glass when the cell contacts a flat surface. Producing the cell involves spraying the luminescent material onto the inside of a metal tube. The metal tube receives the luminescent material while both heated and spinning. The spinning, heated cell can receive a multitude of coats of material at each application and, thus, prepares for use rapidly and economically. Subsequently, the substantially clear glass bonds sufficiently far inside of the tube over its open end to provide the recessed configuration.

Abstract: In the apparatus disclosed herein, a continuously operative sample intake is traversed along the shoreline at a preselected subsurface level appropriate for picking up effluents emanating from on-shore septic systems. The conductivity and the fluorescence of the sampled water are measured continuously, the wavelength of the fluorescence measured being chosen to determine the presence of aromatic hydrocarbons and detergent whiteners which are present in distinctive proportions in recharged septic effluents. Signal processing means are incorporated for generating an output signal which varies as a function of the conjoint deviation of the two measurements from the values thereof which are representative of background water levels.

Abstract: Inert gas under pressure forces a suspension of particles in a carrier fluid through a flow channel including tubes of narrow diameter at a pressure high enough to establish laminar flow free from turbulence at a speed determined by a constant displacement rate syringe at the downstream end of the flow channel. At at least two locations along the flow channel measurements are made of particle conditions, such as radioactivity and size, to provide a multiple of particle signals which are correlated to provide a multi-dimensional characterization of the particles, such as the number of cells exceeding a predetermined radioactivity level for each of a number of cell size ranges.

Abstract: An apparatus for measuring concentration of radioactivity in a fluid circulating in a cooling system or a disposal system, etc. of a nuclear power plant (e.g. coolant), the apparatus having a plurality of sampling tubes with different diameters depending on the intensities of radioactivity, and the sampling tubes having valves for switching from one fluid to another fluid. The sampling tubes are connected to the system to a discharge pipe, and are disposed in the proximity of a radiation detector adapted to issue a signal representative of radiation. The issued signal is supplied to a multichannel pulse height analyzer and a data processing system providing an indication of the concentrations of radioactivities for respective radionuclides.

Abstract: There is provided an improved radon-222 detector device for counting alpha particles originating from radon-222 gas including an alpha particle permeable window in one end of a body and a surface barrier type semiconductor detector adjacent thereto and spaced from the window, and characterized by a moisture attenuating means adjacent the window and the detector.

Abstract: Method of determining the activity concentration of the radio nuclides in waste gases of nuclear power plants by bleeding a part of the gas stream, compressing it to a high superatmospheric pressure, passing the compressed gas into a high pressure chamber where the specific nuclides are measured by means of a calibrated Ge (Li) detector, and returning the gas from the chamber at reduced pressure to the gas stream. The activity concentration of the gas in the high-pressure vessel permits measurement of the specific nuclides, and also permits detection of waste gas activities which are below the customary detection limits.

Abstract: A system for indicating radiation from a radioactive fluid such as a gas wherein simultaneous indications of the activity concentration of radioactivity of the gas, the radiation dose rate and average energy of the radiation are provided.

Abstract: A shielded container in which a vial containing a radioactive solution is housed. The container is constructed so that the activity of the radioactive solution can be measured in a radioisotope calibrator without exposing the technician to potentially harmful radioactivity.

Abstract: The concentration of boron dissolved in water is determined by positioning a measuring vessel between a radio-active neutron source and a neutron detector. The neutron source is disposed in a moderator and the detector is disposed in a relfector; while the test specimen, e.g. boric acid, is disposed between two flat parallel plates perpendicular to the path between the source and the detector. The time necessary for the detector to receive a certain number of neutrons varies linearly as the concentration of boron; and so the boron concentration can be displayed as a function of elapsed time in excess of that time necessary for the predetermined number of neutrons to be received through pure water.

Abstract: A portable radon daughter dosimeter unit used to measure Radon gas alpha daughters in ambient air. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as in uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout displays the result in terms of working level-hours.

Abstract: A method and system to continuously monitor the radon concentration in air. As disclosed, these readings are made in situ in a uranium mine to indicate whether safe working conditions exist therein. The apparatus forming this invention has one or a series of detectors each having: a filter network; a flow control valve; a scintillation cell; a flow meter; a gas pump; a photomultiplier tube with a voltage control circuit; and a signal discriminator with an amplifier and shaper circuit. External of the detectors and connected thereto is a counting and recording system which counts and records the voltage pulses which are indicative of the alpha count on the detector cell. When connected seriatim each detector can be sequentially monitored for a predetermined time interval by the counting system so that the local radon level can be continuously monitored for 24 hours per day seven days a week.

Abstract: Alpha emitters for low-level radiochemical analysis by measurement of alpha spectra are positioned precisely with respect to the location of a surface-barrier detector by means of a chamber having a removable threaded planchet holder. A pedestal on the planchet holder holds a specimen in fixed engagement close to the detector. Insertion of the planchet holder establishes an O-ring seal that permits the chamber to be pumped to a desired vacuum. The detector is protected against accidental contact and resulting damage.

Abstract: A gamma activity counter apparatus for use in automated radioimmunoassay systems including a scintillator counter which has two scintillator crystal-photomultiplier tube assemblies removably contained within a lead radiation shield. Each crystal has formed in it a sample receiving zone, each zone communicating with vertical bores formed in the radiation shield, so that a lifting means can lift sample carriers disposed beneath and in alignment with the sample receiving zones into the zones for gamma activity counting. The lift means is so designed that for each counting period, a pair of sample carriers, separated from each other by an even number of sample carrier spaces, is lifted into the sample receiving zones for simultaneous counting, the sample carriers being contained in holders that are continually advanced over the lift means in increments of two sample carrier spaces per increment.

Abstract: A device for measuring the wear of a radioactively marked machine component by sensing the presence of radioactive wear fragments in a lubricant has a flow-through chamber; an inlet for tangentially introducing the lubricant into the flow-through chamber; a radiation detector at least partially surrounded by the flow-through chamber; and an outlet for removing the lubricant from the flow-through chamber. The device further includes an outer hollow cylinder having a closed radial end face; an inner hollow cylinder having a closed radial end face and an outer diameter which is smaller than the inner diameter of the outer hollow cylinder. The inner hollow cylinder is supported coaxially within the outer hollow cylinder and the space between the two cylinders constitutes the flow-through chamber. The cylinders are supported in a substantially horizontal orientation.