SU708524A1 - Device for interfacing two meters of the same parameter - Google Patents

Description

I

The inventions relate to radio engineering and can be used in various measurement systems that are affected by interference.

A device is known for interfacing two different meters of the same parameter, containing sequentially connected blocks of readout, a narrow filter and an adder, the second input of which is connected to the first input of the subtractor to which the signal from the output of one of the meters is fed, the output of the other meter connected to the second kaotsu of the fl subtraction unit} However, the known device does not provide high accuracy of matching when there are broadband random noises at the inputs of both meters with overlapping spectrum E.

The circuit of the invention is to improve the accuracy of matching by reducing the measurement error in the case of wideband random noise with overlapping spectra.

To do this, in the device the interface of two different meters of the same parameter, containing a series-connected subtraction unit, a narrow-band filter and an adder, the second input of which is connected to the first input of the subtraction unit to which the signal from the output of one of the meters is fed, the output of the other meter connected to the second input of the subtraction unit; the first and second wideband filters and an additional adder are introduced; the second input of the subtraction unit is connected to the input of the first wideband filter, the output of which It is connected to the first output of the additional adder, the other input of which is connected to the output of the adder via the second wideband filter.

The drawing shows a structural electrical circuit of the device for interfacing two different meters of the same parameter.

Claims (2)

The device comprises a subtraction unit 1, a narrowband filter 2, an adder 3, a first wideband filter 4, a second wideband filter 5, an additional adder 6, as well as two inputs 7.8. A device for interfacing two different meters of the same parameter works as follows. The input 7 of the device and the first input (subtraction) of the 1 subtraction unit from the first meter receive the sum of the measured value A, random wide: polished noNJexH B1 with zero mean value and variance D1, as well as narrow-type low-frequency interference C of the drift type zero To the input 8 of the device and the second. B. INPUT (addition) of unit 1 subtraction from the second meter measures the same measured value A and randomly - broadband interference B2 with zero mean value and dispersion D2. As a result, the output of the subtraction unit 1 produces only the difference of the noise B2 81 C. The transmission coefficient of the narrow-band filter 2, which can be linear or non-linear (stationary or controllable) K (S), is chosen so as to pass with the least distortion only narrowband interference C. As a result of adding in the sum of the 3 code signals of the narrow band filter 2 and the first code signal, the signal about (. (B2-B1) - (1- | b), C + A + B1 + C (1 - oC) -B.1 + ft-C + oL. B2, where d. and b are mild values, taking into account the non-ideality of separation n Omex narrow strip filter 2. In the additional adder 6, the signals that pass the first and second wideband filters 4 and 5 are added. The frequency characteristics of these filters should be uniform within the spectrum of the measured quantity A (i), and the coefficient of the cyclists I.X transmission within these limits equal to K2 and KZ 1 - K2. In this case, the output signal of the additional adder 6 will be equal to A + K2 (1 - d.) - BJ. + 1 - К2- (1 -d) 382+ К2- Ъ С. At К2 1 (), the just-written expression will characterize the output signal of the known Psgwa device, namely А + (1 - OL) В1 + d.- В2 + р C. From a comparison of the floor; .x signals, it can be seen that, in the known device, narrowband interference C is strongly attenuated, and wideband.; -: l 81 is practically not compensated. In the ycrpoiicriK p.i iHOFTa, Ti, nredlag-asyom, by choosing the K2 1 value, it is possible to achieve an additional value of both narrowband interference C and wideband interference B1 and B2. This shows, for example, that at C ° and B 0 and full overlapping of the interference spectra B1 and selection 82 / (D1 + D2) reduces the narrowband interference (D1 + D2) / D2 times and reduces the full dispersion of the output wideband interference to D1- D2 / (D1 + + D2). In particular, with D1 D2, putting K2 O, 5, we obtain a reduction in the total dispersion of the interferences B1 and B2 and an additional attenuation of the interference C by half. Thus, the accuracy of the device proposed is higher than that of the known device. Comparative analysis showed that when using the proposed device for pairing two different meters of the same parameter, the total dispersion of the random measurement error can be reduced to two times. Claims An apparatus for interfacing two different meters of the same parameter, containing its series-connected subtraction unit, narrowband filter and adder, the second input of which is connected to the first input of the subtraction unit, to which the signal from the output of one of the meters, the output of the other The meter is connected to the second input of the subtraction unit, which is so that, in order to improve the accuracy of the matching by reducing the measurement error during wideband random noise with overlapping spectra the first and second wideband filters and an additional adder were introduced, while the second input of the subtraction unit is connected to the input of the first wideband filter, the output of which is connected to the first output of the additional adder, the other input of which is connected to the output of the adder via the second wideband filter. Sources of information taken into account at the excursion 1. Chslpikov I. B, Optimum about) G. working signals in the plvivatschdkh sstom-chh, M., Nauka, 1967, about. 1GO.