SU542406A1 - Radioactive isotope device for checking moisture content - Google Patents

Abstract

A RDZIO ISOLATED DEVICE FOR MONITORING MOISTURE, containing: a source of neutron and gamma radiation, a detector of slow-neutrons, a detector of gamma-quanta and an information processing unit, including a correlation circuit of the counting rate of pulses arriving at its inputs from the output of the slow neutron detector gamma quanta detector output, characterized in that, in order to increase the sensitivity, a fast neutron detector was introduced into it, a scheme for measuring the ratio of the pulse count rates arriving at its inputs from the detector The fast neutron pa and the second output of the gamma quanta detector, and the measuring circuit of the ratio of the signals arriving at its inputs from the output of the correlation circuit and the measuring circuit of the ratio of the pulse count rates, are included in front of the indicating device.

Description

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The invention relates to a control measuring technique — radioisotope moisture meters and can be used, for example, in the building materials industry. The known devices for controlling the humidity of materials make it possible to determine the desired parameter by the degree of attenuation of the flux of fast neutrons or by the intensity of the flux of slow neutrons. A common disadvantage of these devices is the relatively low sensitivity. The closest technical solution to the proposed is a device for controlling the moisture of the flowing material on the transport tape. The device contains a source of fast neutrons and gamma quanta, a gamma radiation detector, a slow neutron detector and a registration unit, including an impulse correlation circuit for the counting rate of pulses coming from a slow neutron detector and a gamma ray detector. The disadvantage of this device is that the flux of slow neutrons generated in a controlled object is a slowly varying function of humidity, which causes a relatively low sensitivity of the analysis. The aim of the invention is to increase the sensitivity of the device. The goal is achieved by additionally introducing a fast neutron detector, a circuit for measuring the ratio of pulse count rates to its inputs from the output of a fast neutron detector and a second output of a gamma quantum detector, and a circuit for measuring the ratio of signals to its inputs from the outputs of the correlation circuit; and, a circuit for measuring the ratio of pulse count rates, turned on in front of the indicating device. Fig. 1 shows a proposed radioisotope device for controlling humidity; FIG. 2 shows a change in the readings of an instrument that records only slow neutrons, is an increasing function of humidity (curve a), and a change in readings of an instrument that detects only fast neutrons is a decreasing function of humidity (curve B), then the ratio of the first function to the second gives a dependence that grows faster (curve in), which provides an increase in the sensitivity of the device. The device consists of a source of neutron and gamma radiation (for example, Cf) 1; a slow neutron detector (e.g., a slow neutron scintillation detector) 2; a gamma quantum detector (e.g., a gamma quantum scintillation detector) 3; a fast neutron detector (e.g. a fast neutron scintillation detector) 4, pulse correlation schemes 5, received from the detector slow neutrons and a gamma-ray detector, a circuit for measuring 6 the ratio of the intensities of fluxes of fast neutrons and gamma-quanta (for example, a circuit for measuring the ratio of the frequency of following pulse signals from a metering device awn), measuring circuit 7, the ratio of the flow rate of slow and fast neutrons (e.g. measurement circuit relationship slowly changed S. GCN-voltage d.c.) and indicating device 8, The apparatus operates as follows; Fast neutrons and gamma quanta that passed through the controlled object 9 are recorded by a fast neutron detector 4 and a gamma quantum detector 3, the pulse signals from which are fed to the count rate ratio measurement circuits 6. Slow neutrons produced in a wet controlled object 9 are recorded by the detector 2, Pulse signals from detectors 2 and 3 are fed to the correlation circuit 5, From the output of circuits 5 and 6, the signals are sent to the measurement circuit 7, the signal from the latter is fed to the indicating device 8, graduated in units ah humidity.

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Claims (1)

A RADIOISOTOPE HUMIDITY CONTROL DEVICE, comprising a neutron and gamma radiation source, a slow neutron detector, a gamma-ray detector, and an information processing unit including a correlation circuit for the count rate of pulses arriving at its inputs from the output of the slow neutron detector and one output of the gamma detector -quantums, characterized in that, in order to increase the sensitivity, a fast neutron detector is introduced into it, a circuit for measuring the ratio of counting speeds of pulses arriving at its inputs from the output of the 'detector and fast neutrons and second output gamma ray detector and measurement circuit attitude signals at its inputs from the output of the correlation circuit and the measuring circuit relationship pulse count rates included in front showing the instrument. SU,. 542406