SU620910A1 - Arrangement for measuring four-pole network attenuation - Google Patents

Description

(54) DEVICE FOR MEASURING THE FOUR-POLE DUMP MEASUREMENT

The invention relates to a measurement technique and can be used to measure the secondary parameter of a coaxial communication cable - attenuation.

A device for measuring the attenuation of a quadrupole is known, which contains a signal source, two phase shifters and a selective zero — an indicator, to the inputs of which a sample attenuation measure and the quadrupole 1 under investigation are connected.

However, in the known device, the measurement accuracy is insufficient.

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

To do this, in the device for measuring the attenuation of a quadrupole containing a signal source, two phase shifters and a selective null indicator, to the inputs of which a sample attenuation measure and the quadrupole under study are connected, the output of the signal source is connected to the inputs of phase shifters through an additionally introduced amplitude adjustment unit, between one phase shifter and an exemplary measure of attenuation and between the other phase shifter and the studied quadripole introduced matching amplifiers, whose inputs respectively were connected Yucheny to the two inputs of the additionally introduced indicator of equality am.titud; the exemplary attenuation measure is in the form of an inductive voltage divider.

The drawing shows the structural electrical circuit of the device for measuring the attenuation of a quadrupole.

Claims (1)

The proposed device contains a signal source 1, two phase shifters 2, 3 and a selective zero indicator 4, to which inputs a sample attenuation 5 and a quadrupole 6 under investigation are connected, and the output of signal source 1 is connected to the inputs of phase shifters 2 and 3 through the additionally introduced adjustment block 7 amplitudes, and between one phase shifter 2 and an exemplary attenuation measure 5 and between another phase shifter 3 and the quadripole 6 under study 6 matching amplifiers 8 and 9, the outputs of which are connected to two inputs, respectively, complement the amplitude equality indicator 10 entered in amplitude, with the sample attenuation measure 5 being in the form of an inductive voltage divider. The device works as follows. Sinusoidal voltages are applied to the inputs of an exemplary attenuation measure 5 of the quadrupole under study, the amplitudes of which are controlled by the additionally introduced indicator 10. Adjusting the exemplary attenuation measure 5 to the zero indicator 4 sets the minimum reading, then adjusting the phasers 2 and 3 to improve the initial balance of the circuit. In this case, the violation of the equality of the amplitudes of the input voltages on the exemplary measure of attenuation 5 and the quadripole under study 6 can occur. With the additionally introduced amplitude adjustment block 7, the disturbed equality of the input voltages | Ui | J.Uil, as evidenced by the zero reading of the additionally introduced amplitude equality indicator 10. The attenuation of the investigated quadrupole b in Hp (F) is determined by the formula 1 l, where X is the indication of an exemplary attenuation measure 5. {The value of T is found in the mathematical tables). Using the proposed device, the overall economic effect will be 1,300 rubles per year and at the same time the accuracy of measurement and coordination of cables with amplifiers (during installation) will increase, which will significantly improve the quality of the transmitted information via communication lines. Apparatus of the device for measuring the attenuation of a quadrupole containing a signal source, two phase shifters and a selective null indicator, to the inputs of which a sample attenuation measure and test quadrupole are connected, in order to increase the measurement accuracy, the output of the signal source is connected to the inputs of phase shifters through additionally introduced amplitude adjustment unit, and between one phase shifter and an exemplary attenuation measure and between another phase shifter and a quadrupole under study ohm, matching amplifiers are introduced, the outputs of which are respectively connected to the two inputs of the additionally introduced amplitude equality indicator, while the sample attenuation measure is in the form of an inductive voltage divider. Sources of information taken into account in the examination: 1. US Patent No. 3474336, cl. 324-58, 1969.