B.A. Atayants – Ph.D.(Eng.), General Director of 

LTD enterprise «KONTAKT-1» (Ryazan)

E-mail: market@kontakt-1.ru

V.M. Davydochkin – Ph.D.(Eng.), Head of Department of Microwave Oven of Devices and Aerials,  LTD enterprise «KONTAKT-1» (Ryazan)

E-mail: skb@kontakt-1.ru

V.V. Ezerskiy – Dr.Sc.(Eng.), Professor, Department «Radio Control and Communications»,  Ryazan State Radio Engineering University

E-mail: ezerski@yandex.ru

Assessment of influence of frequency dispersion in a wave guide and sticking of rainfall to wave guide walls to the frequency level gage on the basis of weight averaging of frequency is executed. The possibility of adaptation of a method of weight averaging to the size of equivalent dielectric permeability of the dielectric filling a wave guide is shown, the caused parasitic frequency modulation caused by dispersion in the waveguide path. Quantitative estimates of an achievable error of measurement are given and comparison with a spectral method of a signal of differential frequency is executed. Advantage of a method of weight averaging is shown.

For precision measurement of level of liquids in various technological processes the waveguide frequency-modulated range finder is often used. The punched wave guide is lowered vertically in liquid and the measured distance to the surface of liquid is recalculated in level. For performance of similar measurements it is expedient to use a method of weight averaging of differential frequency. Dispersive properties of a wave guide and sedimentation of rainfall on walls of a wave guide complicate measurement of distance. Dispersive properties of a wave guide are rather easily considered by nonlinear change of temporary scale of weight function. Existence of rainfall causes change of speed of distribution of an electromagnetic wave in a wave guide and respectively to a big error of measurement of distance. It is possible to consider influence of rainfall with use of a concept of equivalent permeability of the dielectric filling a wave guide. For assessment of this size it is offered to use performance of measurement in two identical frequency ranges making the full range of frequency modulation. For this purpose expression for calculation of dielectric permeability by results of distance assessment is given in these subranges. Similar calculations are carried out iteratsionno before achievement of the set error of assessment of value of dielectric permeability. Then with use of the received assessment calculation of distance in the full range of reorganization of frequency is carried out. Quantitative assessment is executed by means of modeling of process of measurement against the background of noise. Comparison of the received results with the similar calculations based on a spectral method of assessment of differential frequency is carried out. It is shown that weight averaging in this case allows to reduce approximately by 10 times the size of an error and to carry out calculations by 30−40 times quicker.

1. Atayants B.A., Davydochkin V.M., Ezerskii V.V., Parshin V.S., Smolskii S.M. Pretsizionnye sistemy blizhnei chastotnoi radiolokatsii promyshlennogo primeneniya. M.: Radiotekhnika. 2012. 512 s.
2. Atayants B.A., Davydochkin V.M., Ezerskii V.V. Tochnost izmereniya urovnya volnovodnym chastotno-modulirovannym urovnemerom. Radiotekhnika. 2015. № 5. S. 73−79.
3. Atayants B.A., Davydochkin V.M., Ezerskii V.V. Adaptivnaya kompensatsiya v chastotnykh urovnemerakh parazitnoi chastotnoi modulyatsii, vyzvannoi nalichiem dispersii. Radiotekhnika. 2015. № 11. S. 73−79.
4. Davydochkin V.M., Davydochkina S.V., Ezerskii V.V. Snizhenie pogreshnosti izmereniya urovnya zhidkosti volnovodnym urovnemerom s chastotnoi modulyatsiei, vyzvannoi narastaniem osadkov na stenkakh volnovoda. Tsifrovaya obrabotka signalov. 2019. № 1. s.
5. Ezerskii V.V., Baranov I.V. Analiz metodicheskoi pogreshnosti datchika rasstoyaniya na baze ChM dalnomera s vesovym sglazhivaniem diskretnoi oshibki. Vestnik Ryazanskogo gosudarstvennogo radiotekhnicheskogo universiteta. 2003. № 11. S. 61−65.
6. Ezerskii V.V., Baranov I.V. Minimizatsiya pogreshnosti izmereniya rasstoyaniya pri tsifrovoi obrabotke signalov chastotnykh dalnomerov promyshlennogo primeneniya. Vestnik Ryazanskogo gosudarstvennogo radiotekhnicheskogo universiteta. 2008. № 24. S. 55−59.
7. Ezerskii V.V., Baranov I.V. Optimizatsiya parametrov modulyatsii v blizhnei chastotnoi radiolokatsii pri vesovom usrednenii raznostnoi chastoty. Vestnik Ryazanskogo gosudarstvennogo radiotekhnicheskogo universiteta. 2009. № 28. S. 30−67.
8. Davydochkin V.M., Ezerskii V.V. Adaptivnaya minimizatsiya pogreshnosti izmereniya rasstoyaniya v chastotnykh urovnemerakh s vesovym usredneniem raznostnoi chastoty. Radiotekhnika. 2016. № 8. S. 91− 97.
9. Davydochkin V.M. Preobrazovanie Fure v zadache izmereniya rasstoyaniya chastotnym dalnomerom v prostranstve s dispersiei. Tsifrovaya obrabotka signalov. 2015. № 1. S. 66−70.