SU938224A1 - Proton magnetometer - Google Patents

Description

The invention relates to magnetic measurements and is intended to measure weak magnetic anomalies in a rapidly changing magnetic field of the Earth.

A proton magnetometer is known, ^{1 * * * 5} consisting of a sensor, a precession signal amplifier, a filter, a phase-locked loop multiplier, a counter, a command device, a matching circuit, and a switching device of the CC.

However, during the operation of this proton magnetometer, it is necessary to continuously adjust the synchronous polarization mode, since the pulse determining the beginning of polarization from one of the divider triggers is tightly connected to the front of the precession signal at the output of the limiter, therefore, in order to compensate for the phase shifts created by the circuit sensor, the amplifier and the multiplier must manually select the position of this pulse, and when changing the frequency of the input signal, the setting must be done again. Since the frequency of the input signal changes quickly, manual tuning does not allow synchronization with the necessary one. accuracy.

The closest in technical essence to the proposed one is a magnetometer, consisting of a sensor, an amplifier-limiter, a phase detector, a low-pass filter, a controlled oscillator, a frequency divider, a trigger, a controlled multivibrator, a regulator for the current value in the sensor, an indicator of the end of current in the sensor , schemes for turning off the current ποι larization and command device [2).

However, the use of the signal from the output of the amplifier-limiter to start the synchronized multivibrator at the right time provides for the introduction of a controlled delay on

938224 4 pulses using the control unit 9 allows the operation of the frequency divider 8, which was in this state before this point in time. In this case, the divisor. 8 frequencies begins to fill up with pulses of the frequency multiplier 3. By a signal from the command unit 7, the control unit 9 stops filling the frequency divider 8 with pulses from the frequency multiplier 3 at the moment that coincides with the positive edge of the signal at the output of the amplifier-limiter. 2.

In the left state, the frequency divider is located until the end of the frequency measurement by the magnetometer counter 4 and then, by the signal from the command unit 7, synchronously with the positive edge of the signal from the output of the amplifier of the limiter 2, the control unit 9 again allows the passage of pulses from the output of the frequency multiplier 3 to the input of the frequency divider 8 . According to the signal of the command unit 7, in parallel with the signal front from the output of the frequency divider 8, the polarization current former 6 is turned on, after which the frequency divider 8 is brought into the zero state. The stop of the frequency divider ₄ 8 is necessary to prevent its malfunction during the transition process of switching on the frequency multiplier 3. A new start of the frequency divider 8 is carried out synchronously with the same edge of the signal of the amplifier-limiter 2 as the stop, which allows the divider to continue working with this information.

The proposed allows automatic synchronous polarization in the entire range of operating frequencies of the device, as well as when working in fields with a gradient of 0.5 nT / m and higher (with a normal gradient of 0.003 nT / m) with a speed of 1, 2,3 and 4 measurements in second and a standard error of no more than 0.2-1.0 nT. This increases the likelihood of detecting small anomalies against the background of the rapidly changing magnetic field of the Earth.

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of the relay, through the contacts of which a polarization current is fed, and the delay time must be a multiple of the duration of the precession signal period, it must subsequently be set again when the operating frequency is changed.

In addition, the circuit does not compensate for the phase shifts created by the sensor loop (with inaccurate tuning) and the amplifier.

The purpose of the invention is improving accuracy and speed.

This goal is achieved in that the proton magnetometer, containing a series-connected Sensor, amplifier-limiter, frequency multiplier and counter, as well as an indicator of the end of the current, the input of which is connected to the second output of the sensor, a polarization current generator, the output of which is connected to the sensor input and the command unit , the output of which is connected to the input of the polarization current driver. It is equipped with a frequency divider, the output of which is connected to the second input of the polarization current driver, and a control unit whose inputs are the outputs of the limiter amplifier, frequency multiplier, the indicator ^ of the end of current and the command unit, and the output of the control unit is connected to the input of the frequency divider.

The drawing shows a functional diagram explaining the operation of a proton magnetometer.

The proton magnetometer contains a sensor 1, an amplifier-limiter 2, a frequency multiplier 3, a counter 4, a current termination indicator 5, a polarization current driver 6, a command unit 7, a frequency divider 8 and a control unit 9, the output of the frequency divider 8 being connected to the input of the driver 6 polarization current, and the input with the output of the control unit 9, the inputs of which are connected to the outputs of the frequency multiplier 3, amplifier-limiter 2, indicator 5 of the end of current and command unit 7.

A proton magnetometer operates as follows. ,

By the signal of the command unit 7, the polarization current driver 6 will stop working, and the current indicator 5 will generate a pulse whose duration is equal to the decay time of the polarization current. Trailing edge of this

3S frequency without potasephase signal pre-technical solution

Claims (2)

1. USSR Author's Certificate No. 705989, cl. (5 01 R 33/00, 1979. 2. US Patent No., cl. 32 + -5, 1969.  five