Magnetic resonance water detection signal detection device and detection method for instantaneous floating point amplification

Abstract

The invention relates to a magnetic resonance water detection signal detection apparatus and detection method based on instantaneous floating point amplification. A preamplifier circuit is connected to a secondary amplifier circuit and an analog switch through a narrow-band filtering circuit. The secondary amplifier circuit is connected to an A / D converting circuit through a high speed program control amplifier circuit. The secondary amplifier circuit is connected to a comparator circuit through an envelope circuit. The analog switch is in separate connection to the high speed program control amplifier circuit, the envelope circuit and a master control circuit. The master control circuit is connected to the A / D converting circuit and the analog switch through a PC 10. According to the invention, the secondary amplifier circuit and the high speed program control amplifier circuit realizes large dynamic range through cascade connection therebetween, which meets the requirement for the detection of large-magnitude varying noise; the apparatus uses the envelope circuit to predict the converting trend of an input signal and provide reference to gain adjustment; the envelope circuit and the comparator circuit which are based on instantaneous floating point amplification achieve the effects of fast pre-anticipation and in-time gain adjustment. Further, no manual operation is required, the work efficiency is increased, and amplifier saturation is effectively suppressed.

Description

technical field [0001] The invention relates to a weak signal detection device, in particular to a magnetic resonance water detection signal detection device and a detection method with a gain self-adaptive adjustment function applied in a nuclear magnetic resonance detection groundwater system. Background technique [0002] The technology of detecting groundwater by nuclear magnetic resonance is a geophysical method that can directly and non-destructively detect groundwater. Due to the weak nuclear magnetic resonance signal, and the large amplitude and mutation characteristics of the environmental noise, it is easy to cause the signal detection and amplification module to saturate. [0003] The "anti-saturation device and anti-saturation method of ground magnetic resonance signal amplifying circuit" disclosed by CN105785458 uses the maximum value of the signal collected in the previous work to set the amplification factor for the next work. Although this method can meet the...

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Problems solved by technology

Due to the weak nuclear magnetic resonance signal, and the large amplitude and mutation characteristics of the environmental noise, it is easy to cause the signal detection and amplification module to saturate

[0003] The "anti-saturation device and anti-saturation method of ground magnetic resonance signal amplifying circuit" disclosed by CN105785458 uses the maximum value of the signal collected in the previous work to set the amplification factor for the next work, although this method can meet the work requirements to a certain extent, but It does not have the function of adjusting the magnification in real time, and in a working process, especially in some environments where the noise mutation is particularly severe, there will still be amplifier saturation.

[0004] CN105974343 discloses the "ground magnetic resonance signal detection device and detection method with automatic gain adjustment function" through pre-sampling to judge the size of the input signal in real time, and the system automatically adjusts the gain to prevent the occurrence of amplifier saturation. The requirements of the effective work of the system, but because the ADC module is used as a pre-sampling, it is difficult to achieve fast gain adjustment, and the dynamic range of the system is limited. In the case of a particularly large change in the noise amplitude, there are still limitations of slow adjustment speed and small dynamic range

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