30 results about "Activity measurement" patented technology

The invention relates to a radiopharmaceutical dosage control system, and belongs to the technical field of radiopharmaceutical measurement. The system comprises: an activity measuring unit for measuring the current radioactive activity of a drug in a target drug storage bottle; the input unit is used for acquiring related basic information of a current medication patient, and the related basic information comprises weight information and height information of the patient; and the analysis unit is used for determining the volume dose required by the currently injected and extracted medicine for the patient according to the radioactive activity of the medicine in the current medicine storage bottle and the related basic information of the current medication patient. The accuracy of medicine dose calculation is improved, and the operation efficiency and the user experience of the system are remarkably improved. Through accurate activity measurement and accurate input of patient information, the system can quickly generate a personalized dosage scheme, errors caused by manual operation are reduced, and the use safety and effect are improved.

The invention relates to the technical field of activity measurement of medical radioactive substances, and discloses a multi-mode activity measurement method and system based on automatic taking and placing of medical radioactive substances, and the system comprises a measurement device and a software control unit, a lead shielding chamber, a plurality of ionization chamber limiting point positions and a gantry structure three-axis linkage mechanism are arranged in a lead glass wall of the measuring device; a plurality of hole point positions used for containing the storage barrels are arranged in the lead chamber body, a mechanical arm used for grabbing the storage barrels is arranged in the three-axis linkage mechanism, the software control unit controls the mechanical arm to move in the X-axis direction, the Y-axis direction and the Z-axis direction, and moving, taking, placing and positioning of the storage barrels between the lead shielding chamber and the ionization chamber are completed. Radiation protection during activity measurement can be achieved, influences of other radioactive substances can be eliminated during measurement, high-precision positioning of medical radioactive substances can be controlled, geometric position consistency during activity measurement each time can be guaranteed, and multi-mode activity measurement of various medical radioactive substances and various activity meters can be achieved.

The present invention relates to the technical field of radiation environment monitoring, and specifically discloses a method for the interim verification of radioactive sources in a radioactive environment laboratory, including the following steps: Step 1: Inspect the appearance of the radioactive source to determine whether there is damage. If damage occurs, it is determined that the verification fails and the source is scrapped; if the appearance is intact, proceed to the next step; Step 2: Use a radiation detector to measure the activity of the radioactive source, and compare the measurement result with the activity of the previous verification certificate after decay correction. If the result is determined to be satisfactory, the interim verification of the radioactive source passes; if the result is determined to be unsatisfactory, recalibrate with a third-party calibration agency. The method of the present invention can keep the radioactive source in a controlled state and ensure the accuracy of the detection results.

The present disclosure relates to a radioactive waste barrel activity measuring device, comprising a chassis and a conveying mechanism arranged on the chassis, the bottom of the chassis is connected with walking wheels, a dose measuring mechanism and a detector assembly are arranged on one side of the conveying mechanism on the chassis, the detector assembly is movably arranged on the chassis to be able to approach or move away from the conveying mechanism, a control system is further arranged on the chassis, and the control system is electrically connected with the dose measuring mechanism and the detector assembly respectively. In this way, the device can conveniently adjust the waste barrel and the radioactive activity measuring device for radioactive measurement, and move to the required measurement site according to the requirement. Through the control system, all running actions of the whole measuring device can be controlled, and the data collected by the dose measuring mechanism and the detector assembly are collected, the efficiency of the activity measurement of the radioactive waste barrel is improved, and the measurement operation of the low-activity radioactive waste barrel is conveniently and quickly completed.

The invention relates to a method and a device for judging the measurement accuracy of reactor core power inclination. The method comprises the following steps: acquiring activity measurement data of a reactor core; constructing a reactor core power equation set based on a corresponding relation between a detector and a reactor core channel in the activity measurement data, and setting a calibration factor of a specified detector in the equation set as a preset value; constructing an error vector, converting the equation set into an error equation by using the error vector, and solving the error equation based on the activity measurement data to obtain a first calibration factor of each detector; determining a power drift factor, converting the equation set into a power drift equation by using the power drift factor, and solving the power drift equation based on the activity measurement data to obtain a second calibration factor of each detector; and according to the first calibration factor and the second calibration factor of each detector, judging the accuracy of the reactor core power inclination result measured by each detector. By adopting the method, the measurement accuracy of the quadrant power inclination of the reactor core can be judged.

The present invention relates to a radioactive drug dosage control system, belonging to the technical field of radioactive drug measurement. The system includes: an activity measurement unit for measuring the current radioactivity of the drug in the target medicine storage bottle; an input unit for obtaining relevant basic information of the current patient receiving the drug, wherein the relevant basic information includes the patient's weight information and height information; and an analysis unit for determining the volume of the drug required for the current injection extraction for the patient according to the radioactivity of the drug in the current medicine storage bottle and the relevant basic information of the current patient receiving the drug. The present invention not only improves the accuracy of drug dose calculation, but also significantly enhances the operation efficiency and user experience of the system. Through accurate activity measurement and accurate input of patient information, the system can quickly generate personalized dosage plans, reduce the errors of manual operations, and improve the safety and effectiveness of use.

The invention discloses an activity value measuring method based on closed-loop feedback and an activity meter. The method comprises the following steps: 1) selecting an activity meter with the same model as a target activity meter as a prototype and placing the prototype in a programmable precision incubator; selecting a standard reference source and placing the standard reference source at a measurement position of the prototype; 2) starting an activity meter to measure the activity value of the standard reference source; calculating a compensation factor measured value under the current combination (T, t); 3) establishing a composite mathematical model CF which takes the temperature T and the operation time point t as independent variables and takes the compensation factor CF as a dependent variable, fitting and solving the measured value of each compensation factor to obtain a specific coefficient numerical value of the model CF, and pre-storing the specific coefficient numerical value into a target activity meter; (4) reading the initial temperature by the target activity meter, and loading a pre-stored composite mathematical model, and (5) collecting the current environment temperature, reading the accumulated operation time, calculating according to the collected radiation signal to obtain an original activity measurement value when the target activity meter is used for radioactive activity measurement, and then obtaining a corrected activity value according to the model.

The utility model discloses an anti-pollution activity measurement sampler, relates to activity measurement technical field, including measuring cup body and sealing assembly, the middle end of measuring cup body top is equipped with cup mouth no. 1, the sealing assembly is provided in measuring cup body top, and the sealing assembly includes transmission shaft, gear, tooth form seal plate, return spring and fixed link, the outer portion of the transmission shaft is sleeved with a gear, the outer side of the gear is connected with a tooth-shaped sealing plate, a reset spring is arranged at an opening in the surface of the tooth-shaped sealing plate, the end of the reset spring is connected with a fixing rod, a cup cover is arranged outside the sealing assembly, and a protruding block is fixed to the inner surface of the cup cover. According to the anti-pollution activity measurement sampler, the anti-slip pad is arranged on the outer surface of the cup cover and used for increasing friction force and preventing the cup cover from slipping when the cup cover is rubbed, and the grid holes annularly distributed below the outer surface of the measurement cup body can enable a radiation source to measure an object to be measured by fully utilizing the penetration characteristic of the radiation source, so that the measurement accuracy is improved.

A measuring station includes a left set of electrodes, including at least two electrically independent electrodes arranged to contact the underside of a user's left foot, a right set of electrodes, including at least two electrically independent electrodes arranged to contact the underside of a user's right foot, a direct voltage source, a switch configured to activate and deactivate a DC configuration in which at least one electrode of at least one set of electrodes is connected to the direct voltage source.

The online detection system for type identification and activity measurement of radiations in gas or liquid is provided, which can capture the light signals generated by different radiations in real time, and convert the light signals into the electrical signals, so as to realize the online type identification and activity measurement of the radiations based on the waveforms and the time information of the electrical signals of the different radiations. In addition, based on the characteristic that different radiations have different penetration capabilities, the inner-outer two-layer activity measurement structure is designed, which can discriminate the radiations with the same waveform. Therefore, the present disclosure simplifies the radiation activity measurement process, thereby greatly improving the efficiency of the radiation activity measurement.

The invention discloses an activity measurement method based on an adaptive coincidence window and dead time correction. The method comprises the following steps: (1) arranging three photomultipliers around a sample to be detected, monitoring three paths of signals generated by the three photomultipliers, and when any path of signal has a rising edge, triggering a self-adaptive coincidence window of which the width is determined by a counting rate R; when R < =, = to ensure that a real coincidence event is captured; at gt; rgt; when R is greater than R, decreasing gradually along with the increase of R so as to reduce accidental coincidence counts; when R > =, = to maximize coincidence efficiency; 2) performing coincidence event judgment in the adaptive coincidence window; the width of the dead time window is adaptively adjusted according to the counting rate R, when R is larger than or equal to R, the width of the dead time window is shorter, and when R is smaller than or equal to R, the width of the dead time window is longer, (4) after the dead time window is finished, normal monitoring is recovered, and (5) when measurement is terminated, the activity of the sample to be measured is reversely deduced through coincidence counting.

The embodiment of the invention provides a coincidence activity measuring device. The coincidence activity measuring device comprises a light-emitting chamber, a light detection assembly and a gamma ray detector. The light-emitting chamber comprises a light-transmitting cavity with a containing cavity and working gas filled in the containing cavity, the containing cavity is used for installing an alpha radioactive source, and the working gas can emit fluorescent light under radiation of the alpha radioactive source. The light detection assembly is arranged on one side outside the light-emitting cavity and faces the alpha radioactive source so as to be used for detecting fluorescence emitted by the working gas. The gamma ray detector is arranged outside the light-emitting cavity and used for detecting gamma rays emitted by the alpha radioactive source. The coincidence activity measuring device provided by the embodiment of the invention is convenient to measure.

This invention discloses a free radical activity measurement system and its application method, relating to the field of atmospheric environmental monitoring equipment technology. The measurement system includes a reaction module, an optical path and light intensity detection module, an air intake module, an air exhaust module, and a free radical detection module. The reaction module includes a main reaction tube and an air intake end and a sampling interface connected to the main reaction tube. The optical path and light intensity detection module emits photolysis laser and absorption laser into the main reaction tube. The air intake module introduces gas into the main reaction tube through the air intake end. The free radical detection module acquires free radicals in the main reaction tube through the sampling interface and measures the fluorescence photon signal of the free radicals. The application method involves performing a single-exponential fitting on the attenuation curve of the fluorescence photon signal to obtain the free radical activity value. This invention can monitor and dynamically adjust the concentration of free radical precursors in real time, achieving accurate measurement of free radical activity under complex external environments, with advantages of high sensitivity and low detection limit.

The application discloses a radioactive source activity measuring device and method, and aims at solving the technical problem of poor measuring result precision and high uncertainty of the existing radioactive source activity measurement. Specifically, the device comprises six detectors and a positive cubic container, and the positive cubic container is used for containing the radioactive source to be measured. The internal cavity of the positive cubic container is also in a positive cubic shape, and the side length of the positive cubic internal cavity is d. The center line through the midpoint of the front and back faces of the positive cubic container is defined as the X axis, the center line through the midpoint of the left and right faces is defined as the Y axis, and the center line through the midpoint of the upper and lower faces is defined as the Z axis. The detection surfaces of the six detectors are respectively opposite to and parallel to the six faces of the positive cubic container. The six detectors are respectively the first detector and the second detector with the central axis along the X axis, the third detector and the fourth detector with the central axis along the Y axis, and the fifth detector and the sixth detector with the central axis along the Z axis.

According to one aspect, a method for determining an augmented vital sign, such as heart rate or heart rate variability, includes obtaining a signal from a patient when the patient is in both active and inactive situations. An activity signal is generated from a first signal and a physiological signal is generated from a second signal. An activity weight factor is calculated from the activity signal and a vital sign signal is calculated from the physiological signal. A mapping from the activity signal to the vital sign helps determine the vital sign over an entire period of motion. The augmented vital sign is a result of a combination of a first value and a second value, the combination including a product of the activity weight factor and an activity-derived vital sign and a product of the vital sign signal and the activity weight factor less than one.

The utility model discloses a device for measuring the activity of a cobalt-60 industrial source. The device comprises a radioactive source bracket and an activity measuring assembly, wherein the activity measuring assembly and the radioactive source bracket are arranged at an interval. A shielding assembly is arranged on the side, away from the radioactive source support, of the activity measuring assembly and used for absorbing rays penetrating through the detection end of the activity measuring assembly. The activity measurement assembly comprises a detection probe, a ray collimation assembly and an installation sleeve shell arranged on the ray collimation assembly in a sleeving mode. The ray collimation assembly is provided with a ray collimation channel. And the detection probe is arranged at the tail end of the ray collimation channel. The ray collimation assembly comprises a plurality of diaphragms which are arranged at intervals, and the diaphragms made of metal tungsten are adopted, so that rays in other directions can be blocked by the diaphragms made of the metal tungsten when being reflected after being in contact with the inner wall, the rays in other directions are effectively prevented from being received by a detection probe, and the detection accuracy is improved. Therefore, the detection result is prevented from being influenced.

The invention discloses a TDCR circular shift wave coupling measurement method under low luminous efficiency, and the method comprises the steps: carrying out the counting measurement of a background solution and a series of quenching sources through a TDCR circular shift wave coupling module, drawing a shift wave quenching correction curve, and further calculating the transition of a sample. The invention also discloses a TDCR circular wave-shifting coupling measurement device under low luminous efficiency, the device comprises a sample bottle and three PMTs which are placed at an included angle of 120 degrees by taking the sample bottle as a center, and the outer wall of the sample bottle is surrounded by an optical coupling silicone oil ring layer and an outer wave-shifting agent layer from inside to outside in sequence. According to the invention, the circular wave shifting module design is adopted, the TDCR technology is combined, so that the Cerenkov measurement efficiency is higher, the device is suitable for activity measurement when the Cerenkov luminous efficiency of nuclides is lower, such as Sr-90 and F-18, the device is matched with multiple bottles of quenching sources to carry out quenching correction, the activity measurement precision is higher, and the stability is better.

The present invention discloses a radiopharmaceutical activity measurement device and method based on passive efficiency scale, comprising a detector base, a CZTγ spectrum detector, a sample tray, a sample holder, and a stopper, wherein the CZTγ spectrum detector is placed on the detector base; the sample holder is fixed above the detector base; the sample tray is horizontally arranged in the sample holder; the sample tray is used to place a radioactive solution container, and the radioactive solution is placed in the radioactive solution container. The present invention uses a new semiconductor CZTγ spectrum detector to record the γ rays emitted by the radiopharmaceutical, and identifies different nuclides through the γ-ray spectrum. The present invention can measure the activity of radiopharmaceutical samples under any conditions, and is not limited by the geometric shape and material of the radiopharmaceutical container, the volume of the radiopharmaceutical, the distance and relative position between the sample and the detector, and can meet the needs of multiple scenarios in the diagnosis and treatment of radiopharmaceuticals.

The invention provides a nuclide activity measurement method based on a neural network, and relates to the technical field of nuclide activity measurement, and the method comprises the steps: constructing a coincidence measurement system, obtaining a plurality of groups of counting parameters of nuclides under different beta detection efficiencies through the system, and carrying out the correction processing of the counting parameters, and inputting the corrected counting parameter into a one-dimensional convolutional neural network model, and obtaining the nuclide real activity based on a condition that model output extrapolation is performed until beta detection efficiency is 100%. According to the method, the neural network is adopted to replace a traditional extrapolation fitting method, the nonlinear relation between the nuclide counting rate and the activity is automatically learned, the accuracy and robustness of activity measurement are remarkably improved, the method does not depend on an explicit function form, abnormal data can be effectively handled, the accuracy of beta, gamma and coincidence counting rates is ensured, and the method is suitable for popularization and application. The interference of environmental background and cosmic rays is effectively inhibited, the signal-to-noise ratio is increased, the measurement efficiency is improved, the operation is simpler and more convenient, and the method is suitable for various nuclear technology application scenes.

The invention discloses a water body radioactive activity measuring device and a water body radioactive activity measuring method.The water body radioactive activity measuring device comprises an output assembly, a concentration assembly and a measuring assembly, the output assembly comprises a sample injection unit, a carrier unit and a solvent unit, the sample injection unit is used for outputting a sample to be measured, and the carrier unit is used for loading the sample to be measured; the carrier unit is used for outputting a carrier solution, the carrier solution and a to-be-detected sample are mixed to form a to-be-detected solution, the solvent unit is used for outputting an organic solvent, and the outlet end of the sample injection unit, the outlet end of the carrier unit and the outlet end of the solvent unit respectively form the output ends of the output assembly. The concentration assembly comprises an evaporation dish, the evaporation dish is located at the output end of the output assembly, and the evaporation dish is used for containing an organic solvent after evaporating the solution to be detected into evaporation residues. The measuring assembly comprises a filter cylinder and a detector, the filter cylinder is located at the output end of the evaporation dish and used for intercepting the evaporation residues in the organic solvent, and the detector is used for detecting the count of radioactive particles in the intercepted evaporation residues.

The present invention relates to a radiopharmaceutical dose calculation method and apparatus for pre-injection analysis for imaging. The calculation method comprises: acquiring the current radioactivity of a radiopharmaceutical and a weight and a height of the currently medicated patient; generating a first standard curve on the basis of data in a data lookup table; generating a second standard curve on the basis of a total activity dose formula; and plotting the first standard curve and the second standard curve into a same coordinate system to form two standard curves whose envelopes define a safe medication range and which do not completely overlap, and determining, on the basis of the standard curves, a desired volume of the radiopharmaceutical to be withdrawn for the current injection for the patient. The calculation apparatus can execute the calculation method. The present invention not only improves accuracy of radiopharmaceutical dose calculation, but also significantly improves system operating efficiency and user experience. By means of accurate activity measurement and accurate patient information entry, the system can quickly generate a personalized dose scheme, thereby reducing errors caused by manual operation and improving use safety and effectiveness.

The application belongs to the technical field of lunar soil measurement, and particularly relates to an analysis method for non-destructive measurement of stable metal isotope ratio in lunar soil, which comprises the following steps: step S1, placing a sample (2) to be measured into a reactor (1) to perform irradiation operation, wherein the sample (2) comprises a lunar soil sample and an earth sample, and the earth sample comprises standard substance and neutron fluence rate parameter monitoring material; step S2, after the irradiation operation is completed, cooling is performed, and then a HPGe detector (4) is combined with a digital multi-channel spectrometer (7) to perform radioisotope activity measurement on the activated lunar soil sample; step S3, after the radioisotope activity measurement is completed, the ratio of stable isotope A and stable isotope B in the lunar soil sample is calculated; and step S4, the difference between the isotope ratio of the lunar soil sample and the isotope ratio of the earth sample is calculated. The non-destructive isotope ratio measurement method provided by the application is complementary to the mass spectrometry method such as ICPMS, and more nuclear technology scientific data is provided for non-destructive analysis of lunar soil.

The present invention discloses a patrol meter for gamma ray inspection and activity measurement, comprising a shell, the upper side wall of the shell is rotatably connected with a rotating plate, the end of the rotating plate is connected with a baffle, the lower side wall of the shell is provided with an arc-shaped opening, the arc-shaped opening is provided with an arc-shaped plate, the upper side wall of the arc-shaped plate is fixedly connected with a connecting rod, the upper end of the connecting rod penetrates the shell, the lower side wall of the rotating plate is provided with a slide groove, the inner walls on both sides of the slide groove are provided with limiting grooves, and a slide rod is slidably provided in the limiting groove. The advantage is that the present invention fixes the patrol meter on the arm through the arc-shaped plate and the strap, so that the patrol meter is portable, and the rotating plate is rotated after fixing, so that the baffle no longer blocks the end, which is convenient for the measurement work, and the baffle blocks again after the measurement is completed, avoiding the problem of damage or contamination of the sensor end, and realizing the activity measurement of radioactive nuclides on the basis of gamma dose rate measurement.

The present invention discloses a device and method for accurately measuring the activity of a radioactive body source, aiming to address the technical problem of high uncertainty in existing methods for measuring the activity of radioactive body sources. Specifically, the device and method comprise a first detector, a radioactive body source, a second detector, and a radioactive standard surface source. The radioactive body source contains radioactive nuclides and is a centrally symmetrical structure with two mutually symmetrical and parallel symmetry planes on its left and right sides, respectively. The first and second detectors are disposed on the left and right sides of the radioactive body source, respectively. The central axes of the first and second detectors lie on the same straight line as the line connecting the midpoints of the two symmetry planes of the radioactive body source. The distance between the first detector and the radioactive body source and the distance between the second detector and the radioactive body source are both L. The radioactive standard surface source is placed on the left or right side of the radioactive body source during measurement to calibrate the absorption coefficient μ of the radioactive body source.

The invention relates to a single-nuclide gamma radioactive sample activity measuring system and method, and the system comprises a shielding box body which is located outside a measuring cavity; the measuring cavity comprises a cube detection area formed by six flat-plate-shaped detectors; the height-adjustable bracket is arranged on the flat-plate-shaped detector at the bottom during use and is used for placing a sample to be detected; and the weight sensor is arranged in the shielding box body and is supported at the bottom of the measuring cavity. The measurement method comprises the following steps: calculating the relative deviation of the detection efficiency of each point location and a central point location in a detection area by adopting a Monte Carlo simulation method, and finding a sensitive area; simulating and calculating self-absorption correction factors of different characteristic samples in the sensitive area, and constructing a database; and experimental measurement: placing a sample to be measured in the sensitive area for measurement, automatically weighing, calling the database through sample parameters, and automatically calculating to obtain a measurement result. The method has the advantages of low requirement on sample positioning precision, simplicity and convenience in operation, short measurement time and high efficiency.

The utility model relates to the technical field of radiopharmaceutical activity measurement, in particular to a radiopharmaceutical activity measuring device which comprises a measuring host and an ionization chamber, the measuring host and the ionization chamber are both installed on a base, and a taking and placing mechanism used for taking and placing a sample is arranged on the base on the left side of the ionization chamber. The picking and placing mechanism comprises a bottom plate, an electric push rod is fixedly arranged at the edge of the left side of the bottom plate, a lifting connecting plate is fixedly arranged at the upper end of the electric push rod, a second shaft seat is embedded in the bottom plate on the right side of the electric push rod, a shaft bush is assembled in the second shaft seat, and a supporting rod capable of sliding up and down is inserted in the shaft bush. The upper end of the supporting rod is rotatably connected with the lifting connecting plate through a first shaft seat, and a lifting supporting arm sleeves the annular surface of the supporting rod and is connected with the measuring frame through a plug-in connecting plate. According to the utility model, through the arranged pick-and-place mechanism, a sample automatic pick-and-place function is realized, a sample can be accurately and quickly put into or taken out of the measurement cavity of the ionization chamber, the operation is convenient, and the measurement efficiency is improved.

The application provides a kind of thyroid I-131 activity measurement system based on double-layer detector, for measuring I-131 activity in human thyroid, comprising: double-layer detector, for receiving the gamma ray emitted by I-131 to outside the body and converting the gamma ray into optical signal, with front and rear end CsI (TI) crystal and rear end CsI (TI) crystal arranged in front and rear adhesion;Nuclear electronics equipment, used with double-layer detector, for converting optical signal into electrical signal;Annular band, for fixing adhesion in human neck, with double-layer detector and nuclear electronics equipment arranged inside;Spectrum analysis module, for analyzing according to electrical signal, to obtain the energy spectrum of gamma ray;Detection efficiency calibration module, for calibrating the detection efficiency of double-layer detector, including OTT calibration unit and detection efficiency calibration unit;Energy spectrum analysis module, for analyzing the energy spectrum of gamma ray received by double-layer detector after calibration to obtain I-131 activity.

The invention relates to a radiopharmaceutical dosage calculation method and device for analysis before imaging injection. The calculation method comprises the following steps: acquiring the current radioactive activity of a medicine and the weight and height of a patient taking the medicine at present; generating a first standard curve based on the data in the data lookup table; generating a second standard curve based on a total activity dose formula; and putting the first standard curve and the second standard curve into the same coordinate system to form two standard curves which are enveloped to form a medication safety interval and are not completely overlapped, and determining the volume dose required by the currently injected and extracted medicine for the patient according to the standard curves. The calculation device can execute the calculation method, the accuracy of medicine dose calculation is improved, and the operation efficiency of the system and the user experience are remarkably improved. Through accurate activity measurement and accurate input of patient information, the system can quickly generate a personalized dosage scheme, errors caused by manual operation are reduced, and the use safety and effect are improved.

The invention relates to the technical field of beta activity measurement, in particular to an ionization chamber beta activity measuring device which comprises a top cover and a handle, the handle is fixedly connected to the upper surface of the top cover, a plurality of grooves are formed in the top cover, nuts are in clearance fit with the interiors of the grooves, screws are fixedly connected to the lower portions of the nuts, and the screws are fixedly connected to the upper surface of the top cover. The outer wall of the screw rod is in threaded connection with the shell, and the upper end of the shell is attached to the top cover. The device adopts a beta activity measuring device designed by a small cylindrical ionization chamber, adopts the ionization chamber as a detector, designs a micro-current measuring system with an automatic range conversion function, also designs automatic compensation and current calibration functions, can deduct a background current value, and finally converts the background current value into the radioactive activity of the energy nuclide through automatic operation. The device can be installed in a hot chamber, a shielding chamber and a glove box for use, the beta activity of the radioactive material of 10 mCi to 20 Ci can be accurately measured, the measurement uncertainty is smaller than or equal to 5% (k = 1), and a user can conveniently and accurately master the beta activity in the measured sample material.