RU170095U1 - MAGNETIC SUSCEPTIBILITY METER - Google Patents

Abstract

The device relates to means for measuring the magnetic susceptibility of standard samples used to calibrate magnetic susceptibility logging tools - working measuring instruments. The technical result is to increase the accuracy and reliability of the calibration results of standard samples. The magnetic susceptibility meter contains a power supply unit, a generator, an alternating signal amplifier with a gain sub-band selection device, a synchronous detector, a direct current amplifier, a resistor divider, and an electronic switch equipped with an additional switching device for connecting to the amplifier input a part of the compensation coil signal instead of the receiving coil signal. 1 ill.

Description

The utility model relates to measuring instruments for the magnetic susceptibility of standard samples in laboratory conditions.

A well-known magnetic susceptibility logging tool (RF patent for utility model No. 85684, G01V 13/00, January 11, 2009, published August 10, 2009), comprising a power supply unit, a generator, an alternating signal amplifier, a synchronous detector, a direct current amplifier, an electronic switch and a resistor divider equipped with resistors that form the standard signals, as well as an induction probe including a generator coil, a compensation coil and a receiver coil, the generator coil of the induction probe connected to the generator, an induction compensation coil insulating the probe is connected to a resistor divider, and an induction receiver coil of the probe is connected to the input of the AC signal amplifier and switch.

The disadvantage of the magnetic susceptibility logging tool is that it does not allow to estimate the instability of the magnetic moment of the generator coil when moving the probe into a medium with significant magnetic susceptibility.

The closest in technical essence and the achieved result is a laboratory magnetic logging tool (RF patent for utility model No. 112776, priority dated 08/11/2011) containing a power supply unit, a generator, an alternating signal amplifier, a synchronous detector, a direct current amplifier, an electronic switch and a resistor a divider, as well as an induction probe, and the electronic switch contains an additional switching device, and the alternating signal amplifier is equipped with a gain sub-band selection device, connected with a further switching device.

The disadvantage of the laboratory magnetic logging tool is that it also does not allow to assess the instability of the magnetic moment of the generator coil when moving the probe into a medium with significant magnetic susceptibility. Given that the contribution of the instability of the magnetic moment to the main measurement error is predominant, a reliable estimate of the measurement error is also impossible.

In the proposed magnetic susceptibility meter, new features in comparison with the prototype is that the electronic switch is supplemented by another switching device that controls an additional switch that connects to the amplifier input a part of the compensation coil signal instead of the receive coil signal.

This design is an easy-to-use device that allows you to evaluate in laboratory conditions the instability of the magnetic moment of the generator coil when moving the probe into a medium with a magnetic susceptibility corresponding to the upper limit of the measurement range and, if necessary, adjust the operating mode of the generator to reduce instability to the minimum possible.

In FIG. 1 is a structural diagram of a laboratory magnetic logging tool, where:

1 - power supply;

2 - electronic switch;

3 - generator;

4 - variable signal amplifier;

5 - synchronous detector;

6 - DC amplifier;

7 - induction probe;

R01 ... R5 - resistor divider;

S1 ... S6 - measurement mode switches.

The magnetic susceptibility meter consists of a power supply 1, an electronic switch 2, a generator 3, an alternating signal amplifier 4, a synchronous detector 5, a direct current amplifier 6, an induction probe 7, a resistor divider R01 ... R5, and switches S1 ... S5. The electronic switch 2 is equipped with an additional switching device (not shown), which controls an additional switch S6, which connects to the amplifier input a part of the compensation coil signal taken from the resistor divider resistor R01, instead of the receive coil signal.

The electronic switch 2 is controlled by a recording program installed in a personal computer connected by a communication line with a laboratory magnetic logging tool through a Vulkan V3 digital logging tool, and with its help it provides the choice of the required measurement mode and sub-range.

An example of a specific implementation.

In this example of a specific implementation, the work in the static of the magnetic susceptibility meter is given.

To select the measurement mode (“magnetic susceptibility - stability”), an additional switching device is installed in the electronic switch 2 of the device, controlled by a registration program installed on a personal computer connected by a communication line through a Vulkan V3 logging digital recorder with a magnetic susceptibility meter.

The sequence of actions when using the meter:

The meter is located at a distance of 0.5 m from the standard sample, the magnetic susceptibility of which is closest to the upper boundary of the measuring range of the meter, while the meter and standard sample must be placed on a horizontal non-magnetic and non-conductive frame.

Perform external meter connections, while its output signal is fed to the input of a Fluke 8846A multimeter. After 15-20 minutes after the supply voltage and voltage to the generator are applied to the meter, the second measurement range is turned on and measurements are started to determine the instability of the magnetic moment.

First, the output signal corresponding to the zero magnetic susceptibility U _{0 is} measured with a multimeter. Then, the meter is placed in the borehole of the standard sample so that the center of the probe of the meter coincides with the center of the standard sample, and the output signal U _{1 is} measured. The value of the relative error δ for the instability of the magnetic moment is estimated by the formula

Δ = (U ₁ -U ₀ ) / 100U ₀ ,%.

The magnetic susceptibility meter, proposed as a useful model, is convenient to use and allows one to obtain reliable estimates of measurement error and their minimization.

Claims (1)

A magnetic susceptibility meter comprising a power supply unit, a generator, an alternating signal amplifier, a synchronous detector, a direct current amplifier, an electronic switch and a resistor divider, an induction probe, the electronic switch having an additional switching device, and the alternating signal amplifier is equipped with a gain subband selection device connected to additional switching device, characterized in that the electronic switch contains an additional switching device, controlling an additional switch connecting to the amplifier input a part of the compensation coil signal instead of the receiving coil signal.

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