EA030111B1 - Ultrasonic gas flow meter - Google Patents

Abstract

The proposed invention is related to measurement equipment and can be used for measurement of gas consumption in industry and in the housing and public services sector. The instrument comprises a primary flow rate transducer with two receiving and emitting electroacoustic transducers, an input switching device, an amplifier, an amplitude-time selector, a sounding signal shaper, a coarse counting meter, an interpolation circuit, a subtraction circuit, a dynamic averaging unit, a clock-pulse generator, a time interval former, and a calculator. The receiving and emitting electroacoustic transducers are connected to the sounding signal shaper and to the amplifier that is connected to the coarse counting meter, the interpolation circuit, the subtraction circuit. The first output of the time interval former is connected to the input of the sounding signal shaper and the first input of the coarse counting meter, its second output is connected to the switching device input, the third output is connected to the second input of the interpolation circuit, the fourth output is connected to the calculator input, the calculator output being the output of the device. The clock-pulse generator is connected to the time interval former and to the inputs of the coarse counting meter and of the interpolation circuit. It comprises a window comparator, a measurement switch and a multi-threshold comparator. The input of the window comparator is connected to the amplifier and its output is connected to the time interval former. The second input of the multi-threshold comparator is connected to the dynamic averaging unit, the second input of the multi-threshold comparator is connected to the second output of the time interval former. The first output is connected to the second input of the measurement switch, the output of which is connected to the input of the dynamic averaging unit, the second output of the multi-threshold comparator is connected to the third input of the time interval former, and the third output is connected to the second input of the dynamic averaging unit.

Description

DESCRIPTION OF THE INVENTION TO THE EURASIAN PATENT

(45) Date of publication and issuance of the patent 2018.06.29

(21) Application Number

201600514

(22) The application date is 2016.06.20

(51) Ιπί. C1. C01P1 / 66 (2006.01)

(54) ULTRASONIC FLOW METER GAS COUNTER

(43) 2017.12.29

(96) 2016 / EA / 0039 (ΒΥ) 2016.06.20 (71) (73) Applicant and patent holder:

SCIENTIFIC RESEARCH INSTITUTION "INSTITUTE OF APPLIED PHYSICAL PROBLEMS NAMED AFTER AN

SEVCHENKO "OF THE BELARUSIAN STATE UNIVERSITY (NIIPPP NAMED AFTER A.N. SEVCHENKO BSU); FOREIGN SOCIETY OF LIMITED

RESPONSIBILITY "RUSBELGAZ" (ΒΥ)

(72) Inventor:

Dedovich Nikolay Nikolaevich, Romanov Anatoly Filippovich (ΒΥ), Anufriev Vladimir Nikolaevich ()

(74) Representative:

Yu.Y. Manilov (ΒΥ)

(56) ΒΥ-υ-5266

EA-A1-200900439

Ki-C1-2353905

4P-A-86217677

030111 Β1

030111 Β1

(57) The proposed solution relates to the measurement technique and can be used to measure the gas flow in industry and housing and communal services. The device contains a primary flow transducer with two receiving-emitting electroacoustic transducers, an input switch, an amplifier, an amplitude-time selector, a probing signal driver, a coarse counter, an interpolation circuit, a subtraction circuit, a dynamic averaging unit, a clock generator, a time interval generator, and a calculator. Transmitting electroacoustic transducers are connected to a probing signal driver and an amplifier connected to a coarse counter, an interpolation circuit, and a subtraction circuit. The shaper of the time intervals by the first output is connected to the input of the shaper signal former and the first input of the coarse count counter, the second output is connected to the switch input, the third output is connected to the second input of the interpolation circuit, the fourth output is connected to the device. The clock generator is connected to the time generator, the inputs of the coarse counter and the interpolation circuit. It contains a window comparator, a measurement switch and a multi-threshold comparator. The input of the window comparator is connected to the amplifier, and the output is connected to the driver of the time intervals. The first inputs of the measurement switch and the multi-threshold comparator are connected to the output of the subtraction circuit. The second input of the multi-threshold comparator is connected to the dynamic averaging unit, the third input of the multi-threshold comparator is connected to the second output of the time interval generator. The first output is connected to the second input of the measurement switch, the output of which is connected to the input of the dynamic averaging unit, the second output of the multi-threshold comparator is connected to the third input of the time interval generator, and the third output is connected to the second input of the dynamic averaging unit.

030111

The proposed solution relates to the measurement technique and can be used to measure gas consumption in industry and housing and communal services.

Known ultrasonic gas meter [1], containing a primary flow transducer, driver of the probing signals, switch analog signals, clock pulse generator, amplifier, measuring counter, driver of the digital signal, block the formation of a timing diagram, circuit subtraction codes, multiplier codes, memory coefficients, accumulating adder, code modification scheme, code comparison scheme, comparator and trigger.

The disadvantage of this solution is that maintaining a constant signal level at the output of the receiving sensors is carried out by changing the amplitude of the probing signals, and the adjustment is carried out based on the results of evaluating the received signal only at the next measurement cycle, and the amplitude of the signal at the output of the receiving sensors is indirectly related to the amplitude of the probing signal . It is known that at high flow velocities a significant increase in fluctuations of the received signal is caused due to their scattering on turbulent flow vortices, which is especially true for gas flows with low kinematic viscosity. Moreover, changes in the amplitude of the signal during sounding both downstream and upstream may be two or more times. At high flow rates, this solution does not allow for an on-line monitoring of changes in the received signal, which can lead to failures and errors in recording and measuring signal parameters or to unreasonable adjustments in case of random signal fluctuations.

The closest technical solution is an ultrasonic flow meter [2], which contains a measuring section with transceiver electroacoustic transducers, an input switch, a probing signal generator, an amplifier with automatic gain control (AGC), amplitude-time selector, a coarse count counter, an interpolation circuit, a dynamic averaging block , clock generator, time generator and calculator.

The counter works as follows. Measurements are performed in two cycles: when probing downstream and against the flow of the medium being measured. The input switch provides the transmission / reception of signals from the corresponding electroacoustic converter (EAF) of the primary flow converter. At the beginning of the measurement cycle, a probe start signal is received from the first output of the time slot shaper to the probe shaper circuit, which triggers the formation of the probe signal, and the probe switch signal is sent to the input switch from the second shaper slot output. At the end of the probe trigger signal, a probe signal is generated at the output of the probe signal conditioner and, at the same time, the coarse-count counter is enabled. The signal passed through the measured medium through the input switch is fed to the input of the amplifier with AGC and, after amplification, goes to the amplitude-time selector, which contains comparators to control the signal level. When the amplitude of the oscillation in the received signal exceeds a predetermined threshold level, this oscillation is singled out as a working pulse of the signal. At the moment of transition of the negative front of the working pulse through zero, the time interval is converted into voltage. The conversion interval ends at the pulse edge of the reference frequency from the clock generator. The number of reference pulses from the trailing edge of the sensing trigger signal to the end of the time-to-voltage conversion is fixed by the coarse-count counter as a coarse-reading code of the time interval. With the help of an interpolation scheme, the time interval formed by the amplitude-time selector within the frequency period of the reference clock generator is converted into a code. From the output of the interpolation scheme, the code value enters the dynamic averaging block. To reduce the influence of external factors and increase the stability of measurements in the interpolation scheme, the meter is calibrated according to the duration of the reference clock period. Codes from the outputs of the dynamic averaging unit and the coarse measurement counter are fed to the transmitter, which generates the code for the propagation time of the signal in the measurement channel and calculates the flow parameters. The operation of all the nodes of the device is synchronized by signals from the outputs of the time interval generator.

The disadvantage of this device is that despite the presence of an amplifier with AGC, incorrect measurements of the propagation time of the probing signal are possible in cases when there is an abrupt change in the flow velocity at sufficiently high gas flow rates or in the presence of interference in the measurement channel. These factors lead to large changes in the amplitude of the received signal or the appearance of spurious signals that cannot be promptly taken into account and compensated. A change in the amplitude of the received signal within large limits or the appearance of additional interfering signals leads to the fact that the determination of the working impulse by exceeding the threshold is achieved for different impulses during sounding and against flow, or the working impulse cannot be detected at all. In this case, the meter fails or the temporal parameters of the measured flow are distorted and, consequently, the measurement error increases. This circumstance does not allow the device to operate with abrupt changes in the flow velocity, which limits the dynamic range of measurements.

This proposal solves the problem of increasing the noise immunity of flow measurement and ensuring the measurement of rapidly changing flows with ultra-low power consumption.

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To solve this problem, an ultrasonic gas flow meter is proposed, containing a primary flow transducer with two transceiving electroacoustic transducers (EAP), an input switch, an amplifier, an amplitude-time selector, a probing signal shaper, a coarse counter, an interpolation circuit, a subtraction circuit, a dynamic block averaging, clock generator, time generator, and calculator, with the inputs / outputs of the receiving-emitting electroacoustic converter primary flow converter through the input switch connected to the output of the shaper of the probing signal and the input of the amplifier, the output of which is connected to the amplitude-time selector, the output of which is connected to the first inputs of the coarse counter and interpolation circuit, the outputs of which are connected to the inputs of the subtraction circuit, the output of which is connected with the first input of the dynamic averaging unit, in addition the first output of the time interval former is connected to the input of the probe shaper signal and the second input coarse counter, the second output is connected to the input of the switch, the third output is connected to the second input of the interpolation circuit, the fourth output is connected to the input of the calculator, the output of which is the output of the device, and the clock generator output is connected to the first input of the time interval former, the third inputs of the coarse count counter and interpolation schemes. Additionally, the ultrasonic gas flow meter includes a window comparator, a measurement switch and a multi-threshold comparator, the window comparator input is connected to the amplifier output, and the output is connected to the second input of the time interval former, the first inputs of the measurement switch and the multi-threshold comparator are connected to the output of the subtraction circuit, the second input multi-threshold comparator is connected to the output of the dynamic averaging unit, the third input is connected to the second output of the time interval generator c, and the first output is connected to the second input of the measurement switch, the output of which is connected to the input of the dynamic averaging unit, the second output of the multi-threshold comparator is connected to the third input of the time interval former, and the third output is connected to the second input of the dynamic averaging block.

The problem is solved by introducing a window comparator, a measurement switch and a multi-threshold comparator into the ultrasonic flow meter. The presence of a window comparator allows, by changing the amplitude of the probing signal, to maintain the level of the received signal within a predetermined working window. A multi-threshold comparator monitors the result of the deviation of the measured time intervals along and against the flow from their average values. The magnitude of the deviation in each direction is compared with the established thresholds and by the results of the comparison, further operations are carried out with the measurements obtained. For large excursions, only in one direction, which corresponds to measurements taken on different working pulses when sounding downstream and downstream or when switching to measurements on another pulse, blocking the passage of measurements through the measurement switchboard and their further participation in the calculations is carried out. Deviations exceeding a certain average level and having a different sign generate control signals in the time interval generator for changing (increasing) the measurement frequency and in the dynamic averaging unit to reduce the constant averaging of parameters depending on the rate of change of flow, which increases the measurement accuracy of rapidly changing flows. The presence of a measurement control mechanism increases the noise immunity of measurements and their reliability. The mechanism of adaptive changes in the measurement frequency and constant averaging provides high accuracy in measuring fast-variable flows while maintaining a low overall energy consumption, which is especially important for household gas meters, which should work without changing the battery during the entire calibration interval.

The essence of the proposed solution is illustrated by the block diagram of the ultrasonic flow meter (Fig. 1).

Ultrasonic flow meter contains a primary flow transducer 1 with a set of electro-acoustic transducers (EAP) (EAP1 and EAP2), input switch 2, amplifier 3, amplitude-time selector 4, shaper 5 probe signal, window comparator 6, counter 7 coarse count, circuit 8 interpolations, subtraction circuit 9, dynamic averaging unit 10, clock generator 11, shaper 12 time slots, calculator 13, measurement switch 14 and multi-threshold comparator 15. Receiving-emitting electro-inputs / outputs Busy transducers EAP1 and EAP2 primary flow converter 1 through the input switch 2 is connected to the output of the probing signal conditioner 5 and the input of the amplifier 3, the output of the amplifier is connected to the amplitude-time selector 4 and the input of the window comparator 6, and the output of the amplitude-time selector is connected to the first inputs coarse counter 7 and interpolation circuits 8, the outputs of which are connected to the inputs of the subtraction circuit 9. The first output of the driver 12 time intervals connected to the input of the driver probing the signal 5 and the second input of the coarse count counter 7, the second output of the driver 12 is connected to the second input of the switch 2, the third output of the driver 12 is connected to the second input of the interpolation circuit 8, the fourth output is connected to the first input of the transmitter 13, the second input of which is connected to the output of the dynamic block averaging 10, and the output of which is the output of the device. The output of the clock generator 11 connect - 2 030111

It is connected with the first input of the shaper 12 time intervals, the third inputs of the coarse counter 7 and the interpolation circuit 8, and the output of the window comparator 6 is connected to the second input of the shaper 12 time intervals. The first inputs of the measurement switch 14 and the multi-threshold comparator 15 are connected to the output of the subtraction circuit 9, the second input of the multi-threshold comparator 15 is connected to the output of the dynamic averaging unit 10, the third input is connected to the second output of the time interval former 12, and the first output is connected to the second input of the measurement switch 14 , the output of which is connected to the input of the dynamic averaging unit 10. The second output of the multi-threshold comparator 13 is connected to the third input of the driver 12 time intervals, and the third output with one with a second input of the dynamic averaging unit 10.

The operation of the ultrasonic flow meter counter consists of 2 measurement cycles that correspond to two directions of ultrasonic sounding (along the flow of the medium being measured and against the flow). The flow rate ν is determined by the difference between the propagation times of the signal in flow T ₁ and against flow T ₂ .

The measured time interval during the sounding of the flow T ₁ can be represented as

t, = —-- (1)

c + t ”

When sounding against a stream, the time interval T ₂ is equal to

T ₂ = --- + ^ + 1; (2)

ST * S036G with ~

where b is the path length of the ultrasonic signal in the stream;

L ₀ - ultrasonic signal path length in the stationary medium; c is the velocity of propagation of ultrasound in a stationary medium; ν — flow rate;

1 ₁ - constant delay, not related to the propagation of ultrasound in the medium, when probing downstream;

ί ₂ - constant delay, not associated with the propagation of ultrasound in the medium, when probing upstream;

α is the angle between the direction of flow and the direction of propagation of the ultrasonic signal. Considering that ί _χ «ί ₂ = ί ₀ , and denoting Αί = ί ₂ -ίι and 2 · ₀ = ίι + ί ₂ , after the transformation we get the expression

for flow rate

where Tr = T2 - T1, Tc = T1 + T ₂ ,

B = b + b is the geometric base of the device. Volumetric flow is calculated by the formula

where And - the diameter of the flow meter section.

Volume ν _{0 is} calculated cumulatively in accordance with the expression

= (5)

where T ₁₂ is the interval between measurements.

To perform all the necessary measurements and obtain the values of flow and volume, each measurement cycle includes five time intervals:

sensing interval I! - the formation of the control pulse shaper probe signal and pulse sensing;

measurement interval 1 ₂ - measurement of the propagation time of the probing signal in the primary flow converter;

calibration interval 1 ₃ - measurement of the duration of the reference frequency period;

measurement processing interval 1 ₄ - formation of the resulting value of the measured time interval and selection of measurements;

calculation interval 1 ₅ - calculation of the values of the measured parameters: flow rate and volume of the measured medium.

It should be noted that the first four measurement intervals are performed in each measurement cycle, while the calculation interval is added only after the second measurement cycle of time intervals to calculate the gas flow and gas volume measurements made in accordance with expressions (3), (4) and (5) ).

Depending on the measurement cycle, from the first output of the shaper of 12 time intervals to the input switch 2, a control signal is received, which ensures the transmission / reception of signals to / from the corresponding EAP.

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In each cycle, the following procedures are performed.

At the beginning of the first interval (Σι), the probe start signal 5 from the first exit of the 12 timeslot shaper receives a probe start signal, which controls the start and amplitude of the probe shaper, and the input switch 2 from the second shaper output receives 12 time slots the probe enable signal . Switched EAI determined by the number of working cycle in the measurement cycle. In the flow sensing cycle, the sensing enable signal of the shaper 12 provides the output of the shaper signal's shaper signal 5 through the public key of the input switch 2 to the electroacoustic converter of the EAP1 primary flow converter 1. The second EAA2 is shunted to reduce the mutual influence of the channels. At the end of the probing start signal, the probing signal shaper 5 generates a probing signal, and the coarse count counter 7 starts counting the pulses of the clock generator 11. At the end of the probing signal, the probing enable signal is removed.

At the second interval (Ι ₂ ) of ЭАП2 of the primary converter of the flow 1 through the input switch 2 according to the reception permission signal coming from the first output of the driver 12 time intervals, is connected to the input of the amplifier 3. The sounding signal passed through the measured medium and amplified by the amplifier 3 time selector 4, which contains comparators to control the signal level. When the amplitude of the oscillation in a received signal exceeds a predetermined threshold level, this oscillation is selected as the operating pulse of the signal. The working signal pulse arrives at the window comparator 6, which contains two comparators: the comparator of the upper border of the window and the comparator of the lower border of the window, and two event counters associated with them: the attenuation counter and the gain counter. When the signal amplitude leaves the monitoring window, the corresponding counter counts the number of events. The signal from the comparator's output of the upper boundary of the window goes to the counting input of the attenuation counter and to the reset input of the gain counter. The signal from the comparator output of the lower window border is fed to the counting input of the gain counter and to the reset input of the attenuation counter. The overflow signals of the counters arrive at the shaper of 12 time intervals, which increases or decreases the duration of the control signal supplied to the shaper 5 of the probing signal, thus increasing or decreasing the amplitude of the probing signal. The presence of counters of the number of events ensures the amplitude adjustment only at a steady-state change in the received signal and does not lead to a chaotic reaction to random signal fluctuations.

When the negative front of the working pulse passes through zero, the end of the measured time interval is fixed. This starts the interpolation circuit 8, which measures the time interval within the fixed end of the measured time interval to the pulse edge of the reference frequency of the clock generator 11. On the same pulse of the reference frequency, the coarse count counter 7 stops, the counter code 7 is fixed as a coarse count value time interval.

On the third time interval (Ι ₃ ), the time interval meter is calibrated, i.e. The period of the reference frequency of the clock generator 11 is measured. To determine the code of the period of the reference frequency, the calibration is performed in two cycles: in the first cycle, the third output of the driver has 12 time intervals, the interpolation circuit 8 receives a calibration signal with a duration equal to (n + 1) periods of the reference cycle , in the second cycle - the duration of η periods (n> 1). The code of the reference frequency period K _о is equal to

K _o = K _s11 - K _a2 = (l +1) · £ „- and · £„ (6)

where Xi is the code for the duration of the first calibration cycle,

_K12 is the code for the duration of the second calibration cycle.

The calibration code is fed to the interpolation scheme 8 to obtain the code of the value of the interpolation part of the measured time interval in accordance with the expression

(7)

where K _E - the measured code value of the interpolation interval,

Κ _ΙΝ is the normalized code value.

In the fourth interval (Ι ₄ ), the codes from the outputs of the coarse counter 7 and the interpolation circuit 8 are sent to the subtraction circuit 9, where the code for the resulting time interval, T, is generated; according to the expression

3 = (N-X _I) z ", microseconds (8)

where is the period of the frequency of the reference oscillator in μs,

N is the number of periods calculated by the coarse count counter.

The code value of the propagation time through the measurement switch 14 enters the dynamic averaging block 10, where the measured values of the propagation time are averaged with a fixed averaging constant.

In the multi-threshold comparator 15 by the code of the measured value of the time interval coming from the subtraction circuit 9, and the code of the average value of the time interval from the dynamic block

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averaging 10, codes are formed deviations of the magnitude of the measured value from its average value in the direction determined by the signal from the second output of the driver time intervals.

The deviation codes for each direction of sensing are compared with three threshold values: upper, middle and lower.

When the upper threshold is exceeded only in one direction, which corresponds to the reception of an interfering signal, the signal from the first output of the multi-threshold comparator 15 blocks the passage of measurements through the measurement switch 14 and further participates in the flow measurement, which ensures the noise immunity of the measurement circuit and the reliability of the measurement results.

Deviations exceeding a certain average threshold level and having a different sign, from the second output of the multi-threshold comparator 15, generate control signals to the time interval generator 12 to increase the frequency of measurement of rapidly changing flows.

Exceeding the deviations of a different sign of the lower threshold level leads to the formation of a signal from the third output of the comparator 15 into the dynamic averaging unit 10 to reduce the constant averaging of the flow parameters.

An increase in the measurement frequency and a decrease in the constant averaging provides an increase in the tuning rate and an increase in the accuracy of flow measurements. With a steady stream, the deviations of the current measurements from the average value become small, below the lowest threshold level, and the counter switches to measurements with a low frequency, which significantly reduces power consumption.

In the fifth interval (1 ₅ ), the calculator 13 calculates the flow characteristics in accordance with expressions (3), (4) and (5). The operation of the transmitter 13 is synchronized by signals from the output of the driver 12 time intervals.

The operation of the flow meter is controlled by the driver 12 time intervals. The shaper of 12 time intervals for the input reference clock pulses generates the number of the time interval and the number of the cycle in the measurement cycle, as well as control signals and the code of the number of averages.

The two-channel input switch 2 contains four keys for each channel: a sensing resolution key, a reception resolution key, a sensing shunting key, and a reception shunting key.

In the shaper of the probing signal, in order to form the amplitude of a pulse exceeding the supply voltage of the circuit, the accumulation of energy in the inductance is used when a direct current flows through it. The shaper 5 of the probing signal contains a choke L of energy storage, a voltage doubling circuit and a charging current switch. When a start-up sensing signal is applied, the energy storage choke is connected to the voltage doubling circuit via a closed-loop charging current switch. When the key is opened, through which the current was passed, the throttle current generates a sensing impulse. The duration of the probe pulse is determined by the frequency of the resonant circuit formed by the inductor inductance and the capacitance of the EAP, and its amplitude is determined by the duration of the current flow through the inductance. The resonance frequency of the circuit is chosen equal to the frequency of the mechanical resonance of the EAP. The voltage doubling circuit serves to increase the efficiency of the circuit and the possibility of generating probing signals of large amplitude, several times exceeding the battery supply voltage of the meter (voltage 3.0-3.6 V).

The amplitude-time selector 4 includes two level comparators: a comparator of the operating oscillation threshold and a comparator of the received signal. Comparators provide a selection of working oscillations from the received signal and fixing its temporary position to control the coarse reading circuit 7 and the interpolation circuit 8.

Scheme 8 interpolation is used to determine the exact value of the propagation time of the signal by measuring the part within the period of the clock frequency in accordance with formula (8). The beginning of the measurement interval is set by the comparator of fixing the reception of the amplitude-time selector 4 at the zero crossing of the trailing edge of the working pulse, and the end of the interval - by the working edge of the clock pulse. The value of the time interval is converted into a voltage value using a time-voltage converter, and then into a code by an analog-to-digital converter. To ensure that the measurements are independent of the time-code conversion characteristic, the interpolation scheme on the calibration interval determines the code for the period of the clock pulse.

Dynamic averaging unit 10 is a storage unit with variable accumulation constant. The accumulation constant is adjusted by the multi-threshold comparator 15 depending on the dynamics of flow change.

The multi-threshold comparator 15 includes a code difference calculator, upper, middle, and lower level comparators, a status register, and an analyzer, which consists of three schemes for matching the codes of specific bits of the status register. According to the measurement results, depending on the deviation of the measured values from their average values, fixed in the bits of the comparator 15 status register, control outputs for blocks 14, 12 and 10 are generated at its outputs, which provide for the selection of reliable measurements, changing the measurement frequency and choosing the appropriate degree, respectively. averaging.

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Information sources.

1. Eurasian Patent No. 014208, IPC Θ01Ρ 1/66, published on 10.29.2010.

2. The patent of the Republic of Belarus for useful model No. 5266, IPC Θ01Ρ 1/66, published on June 30, 2009 (prototype).

Claims (1)

CLAIM Ultrasonic flow meter-gas meter containing a primary flow transducer with two receiving-emitting electroacoustic transducers, an input switch, an amplifier, an amplitude-time selector, a shaper of the probing signal, a coarse count counter, an interpolation circuit, a subtraction circuit, a dynamic averaging block, a clock generator, a time interval and computer, with the inputs / outputs of the receiving-emitting electro-acoustic transducers of the primary flow converter through the input A switch is connected to the output of the probing signal shaper and the amplifier input, the output of which is connected via the amplitude selector to the first inputs of the coarse counter and interpolation circuit whose outputs are connected to the inputs of the subtraction circuit, and the first output of the time interval former is connected to the input of the probing signal shaper and the first input of the coarse counter, the second output is connected to the input of the switch, the third output is connected to the second input of the interpolation circuit, the fourth you ode is connected to the input of the transmitter, the output of which is the output of the device, and the output of the clock generator is connected to the first input of the time interval former, the third inputs of the coarse counter and interpolation circuit, characterized in that it further comprises a window comparator, a measurement switch and a multi-threshold comparator, the window comparator input is connected to the amplifier output, and the output is connected to the second input of the time interval former, the first inputs of the measurement switch and the multi threshold the comparator is connected to the output of the subtraction circuit, the second input of the multi-threshold comparator is connected to the output of the dynamic averaging unit, the third input of the multi-threshold comparator is connected to the second output of the time interval former, the first output is connected to the second input of the measurement switch, the output of which is connected to the input of the dynamic averaging unit, the second the output of the multi-threshold comparator is connected to the third input of the time interval former, and the third output is connected to the second input of the block averaging th.