RU1814729C - Device for determining density of surface layer of soil in depth - Google Patents

Abstract

Usage: land reclamation studies in agriculture, the invention can be applied to control the density of the surface layer of soil, which allows to improve the operational parameters of the device. The device contains a source and a γ-radiation detector placed in a radiation protective case 5. In this case, the γ-radiation detector contains a scintillator 2, a photoelectronic multiplier 5 and a power voltage divider 4, the output of which is connected to the input of the spectrometric amplifier 7, and the input is connected to output of an adjustable high voltage source. The input of the latter is connected to the first output of the amplitude selector 8, the input of which is connected to the output of the amplifier 7, and the second output is connected to the input of the information processing unit 10. The device allows for vertical layer-by-layer determination of the density of the surface soil layer without disturbing the natural structure of the soil and sampling, which increases accuracy, efficiency and shortens the time of investigation. 3 ill. (L C

Description

The invention relates to agriculture and can be used to study the water-physical properties of the soil on reclaimed arrays of drainage and humidification systems.

The purpose of the invention is to improve the operational parameters of the device. ; The goal is achieved in that a device for determining the density of the surface layer of the soil, vertically containing a source of radiation, including a scintillator, a photomultiplier tube, a voltage divider and a spectrometric amplifier, are placed in a radiation protective case and connected to the o &

processing the information, further comprises an amplitude selector and an adjustable high voltage source, the input of the amplitude selector being connected to the output of the spectrometric amplifiers, and the first and second outputs connected to the inputs of the information processing unit and the adjustable high voltage source, the output of which is connected to the input of the voltage divider, while the radiation protective casing has a through channel connecting the source and the γ-radiation detector.

Comparative analysis with the prototype shows that this device is from

Ј

Sj

Yu

ABOUT

CA)

This results in the presence of new units: an amplitude selector, an adjustable high voltage source and their connections with the remaining elements of the device, as well as channels in the radiation protective casing.

Comparison of this solution with other technical solutions shows that the blocks introduced into the device are known. However, when they are introduced in this connection with the other elements of the circuit into this structure, new properties appear, then, together with the introduction of a new combined Element, in particular, a through channel for connecting the source and the γ-radiation detector, to the radiation protective housing, it improves operational parameters of the device.

Fig. 1 is a structural diagram of a device for determining the vertical density of a surface soil layer; in Fig. 2 the spectral composition of the γ radiation detected by the detector; Fig. 3 shows the dependence of the depth value (research area) on the initial energy detection threshold.

The device for determining the density of the surface soil layer vertically (Fig. 1) contains a γ-radiation source 1 and γ-radiation detector, including an electron gun 2, a photomultiplier 3 and a power voltage divider 4, placed in a radiation protective casing 5 with a through channel b, a spectrometric amplifier 7, an amplitude selector 8, an adjustable high voltage source 9 and an information processing unit 10. Figure 2 shows the full spectrum 11 of the)-radiation detected by the detector and the thresholds 12,13,14 and 15 of the amplitude selector 8. Figure 3 shows the dependence of the 16 study area (depth) on the energy of the detected γ radiation.

The device operates as follows.

The γ-radiation source 1 emits γ-quanta, which are scattered in the surface soil layer, are detected by a scintillator 2 and converted by a photomultiplier 3 into a sequence of electrical pulses, which, passing through a spectrometric amplifier 7, fall into the amplitude selector 8. Amplitude selector 8 of all The spectrum of the γ-ray detector detected by the detector is distinguished by two channels, the counting and the reference.

The energy range of the counting channel is determined by the required measurement depth; in this case, the maximum depth (20 cm) corresponds to the portion of the spectrum of the recorded γ radiation located between the lower threshold 12 and the upper 14, and the minimum (5 cm) between 13 and 14 thresholds ( figure 2). Therefore, to change

depth, i.e., vertical profiling of the surface soil layer, it suffices to change the initial energy threshold for recording scattered γ radiation using the amplitude selector 8.

Next, the pulses of the counting channel from the first output of the amplitude selector 8 are fed to the input of the information processing unit 10, where they are recorded for a certain time, converted according to a predetermined algorithm, and displayed on the board directly in density units (direct indication).

The reference channel serves to control an adjustable high voltage source 9, stabilizing the gain of the photoelectronic multiplier 3. It is created by extracting from the spectrum of the γ radiation detected by the detector, pulses whose amplitude is greater than the threshold

15. The threshold 15 is set at the top of the reference peak, which is used as a photopeak of direct radiation of the source 1. The reference peak is obtained due to the through channel 6 in the radiation protective casing 5 connecting the γ-radiation source 1 and the scintillator 2. The diameter channel 6, which determines the counting speed of the reference channel, the outcome is selected from the desired high voltage stabilization coefficient, and therefore the gain of the photoelectronic multiplier 3. The length of channel 6 is determined by the size of the probe, i.e. e. the distance between the centers of source 1 and

scintillation torus 2.

The pulses of the reference channel from the second output of the amplitude selector 8 are fed to the input of the high voltage source 9. Deviation count

pulses from the reference channel from a given one leads to a corresponding change in the high voltage at the output of source 9 (with a decrease in the number of counted pulses, the voltage at its output increases, and with an increase it decreases), and consequently, to a change in the voltage applied to the input of the divider voltage 4, thereby stabilizing the photoelectric gain

multiplier 3.

Thus, this device allows, in comparison with the prototype, to determine the density of the surface soil layer vertically, while the density is controlled by layers 0-5, 0-10, 0-15 and 0-20 cm, due to the violation of the natural structure soil and sampling, with high accuracy, rapidity and profitability.

 $

Claims (1)

SUMMARY OF THE INVENTION A device for determining the vertical density of a surface soil layer comprising a gamma radiation source and a gamma radiation detector including a scintillator located in niches of a protective radiation enclosure. a photoelectronic multiplier and a voltage divider, the output of which is connected to the input of the spectrometric amplifier, and the processing unit information, characterized in that, in order to improve the operational parameters of the device, it is equipped with an amplitude selector and an adjustable source high voltage, the input of which is connected to the first output of the amplitude selector, and the output is connected to the input of the lithium voltage divider, while the output of the spectrometric amplifier is connected to the input an amplitude detector, the second output of which is connected to the input of the information processing unit, and a channel is made in the protective radiation casing, which communicates the emitting output of the gamma radiation source with the receiving input of the amplifier. SURFACE M (M LRCHVY L N