SU746698A1 - Noise measuring device - Google Patents

Description

(54) DEVICE FOR NOISE MEASUREMENT

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The invention relates to instrument making and can be used to measure noise, for example, in the in-house diagnosis of various machines and mechanisms.

Device for indiscriminately diagnosing mechanisms and machines are known, comprising a sound meter with a microphone, filters and recorders 1.

The disadvantage of these devices is relatively low measurement accuracy.

Closest to the proposed technical entity is a device for measuring noise, containing an input unit in the form of a signal sensor connected in series, an attenuator, an input amplifier and a recording amplifier connected to a magnetic recording head, a driving mechanism with magnetic media, a magnetic recording head connected through sequentially connected playback amplifier, band-pass filter and detector to one of the inputs of the subtraction circuit, to the other input of which the output of the reference voltage block is connected The accumulators are connected via a vertical scan switch connected in series, a modulator and a second detector connected to vertical deflection plates of a cathode ray tube whose horizontal deflection plates are connected to the corresponding vertical switch commutator 2 via a horizontal scanner.

The disadvantages of this device include a relatively low measurement accuracy.

The purpose of the invention is to improve the measurement accuracy of the device.

The goal is achieved by the fact that the device is equipped with an additional switch, speed switch and software block, with one of the outputs of the software block connected to the speed switch associated with the driving mechanism, the second output with the input of the horizontal scanner and with the corresponding input of the additional switch in the third output is with input 20 of the unit of reference voltages, and the output of the subtraction circuit is connected to storage devices via an additional switch.

The drawing shows a structural diagram of the proposed device.

The device consists of an input unit 1, made, for example, in the form of a sensor, attenuator, input amplifier and recording amplifier (not shown in the drawing) connected to magnetic recording head 2, driving mechanism 3 with magnetic recording medium, magnetic playback head 4 connected through the reproduction amplifier 5, the band-pass filter 6 and the detector 7, to one of the inputs of the subtraction circuit 8, the other input of which is connected through the block 9 of the reference voltages and the program block 10 to the speed switch 11, which changes the speed of recording bodies 3. The output of the subtraction circuit 8 is connected through a series of additional switch 12, accumulators 13, vertical switch 14, modulator 15 and second detector 16 connected to vertical deflection plates of a cathode ray tube (CRT) 17, and software block 10 is connected to an additional switch 12, by a vertical switch 14 and, through a horizontal ramp, a screwdriver 18, is connected to the horizontal deflection plates of the CRT 17.

The device works as follows. -,

An input signal is applied to the input unit 1 of the device, which may be a noise, vibration or other non-electric signal. The magnetic recording head 2 records a signal already converted to electrical on a magnetic recording medium, for example a magnetic drum, rotating at a certain fixed speed.

The reproduction of information is carried out by the magnetic reproduction head 4, amplified in the reproduction amplifier 5 and fed to the input of the band-pass filter 6. In the band-pass filter 6, depending on the analysis purpose, the width of the passband can be changed at a fixed fixed frequency.

In order to decompose the signal under investigation into spectral components, when a signal is passed through a band-pass filter 6, the magnetic recording carrier, due to the speed switch 11, rotates at a tunable speed, so that it can analyze spectral components in the band-pass filter 6 them to a fixed average frequency.

The signal from the output of the bandpass filter 6 through the detector 7 is fed to one input of the subtraction circuit 8, to the other input of which the signal comes from a block of 9 reference voltages, in which the reference voltages of the corresponding spectral components are automatically set, having received a command from the output of the software block 10. To do this in program block 10

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enter the punched card of reference values calculated on a computer.

From the other output of the program unit 10, the speed switch 11 receives the command, and from the third output the additional switch 12, the vertical switch 14 and the horizontal scanner 18.

Thus, the software unit 10 performs synchronous operation of the speed switch 11, with the units of 9 reference voltages, the additional switch 12, the vertical switch 14 and the horizontal scanning unit 18

The resulting signal from the output of the subtraction circuit 8 is fed to the input of the additional switch 12, at the output of which we have pulses that are separate in time with the corresponding amplitudes that go to the corresponding accumulators 13. From the outputs of the corresponding accumulators 13 signals through the serially connected vertical switch 14, modulator 15 The second detector 16 is fed to the vertical deflection plates of the electron-beam tube 17.

Thus, on the cathode ray tube 17 one can visually observe the frequency characteristics of the signal under study, reference levels, as well as the resulting signal of spectral components that can be photographed.

The use of the invention allows to significantly reduce the measurement error and establish automatically reference levels.

Claims (2)

1. Il pike Yu. M. Measurement and rationing of industrial schuma. Profizdat, 1964, p. 26-58. 2. USSR author's certificate No. 283626, cl. G 10 L 1/02, 1970 (prototype). TA