CS256478B1 - Adapter for measuring of inductance and capacity resistances - Google Patents

Abstract

The adapter consists of a basic cuboid body fitted with two connectors connecting the middle conductor. The essence of the adapter is that both circular middle conductors are above the front faces of the adapter and terminating with the measuring terminals, of which one measuring clamp is horizontally slidable The calibration terminals are connected during calibration calibrated intermediate conductor in a Teflon dielectric in a metal body.

Description

Nowadays, a wide variety of methods and instruments are used to measure circuit components, which differ in their intended purpose. The most obvious and most widespread are methods and instruments for measuring the simple value of circuit components, ie resistance, capacitance and inductance. The measurement is usually made with either a DC voltage or an AC signal at a relatively low frequency of about 1 or several kHz. Methods and instruments for measuring simple values of resistances, capacitances and inductances exhibit relatively high accuracy, which is 1% to 0.1%.

However, the values of the circuit elements measured at low frequencies do not fully apply to higher frequencies. Circuit components at higher frequencies change their value, or they use parasitic components, which are undesirable, but for designing RF circuits and accurate knowledge of the function it is necessary to know them. Therefore, circuit components are measured on devices whose specific frequency is higher or varies to several MHz or hundreds of MHz.

Various impedance meters are used for this, where the component to be measured is either plugged directly into the instrument terminals or mounted on the probe input or the impedance is measured directly in the circuits with the probe. At the highest frequencies in the range of 500 MHz and above, the measured component is inserted directly into the coaxial or high-frequency line and its value is calculated from the measured voltages and phases. These measuring methods evaluate both the real and reactive component of the measured element either in Cartesian or polar coordinates. Unlike simple RLC meters, high frequencies do not reach high

256 478

Even measurement accuracy. One of the methods of measuring the impedance of RLC circuit components is the divider method, which requires special tools - adapters to connect to, for example, a circuit analyzer.

It is an object of the present invention to provide an adapter for measuring inductance and drip resistances consisting of a basic cuboid body provided with two coaxial connectors with central circular conductors. It is an object of the invention that the circular center conductors mounted in the Teflon core in the base body extend at right angles to the front plane of the adapter and terminate with the measuring terminals, the first center conductor with the first measuring terminal connected to the first connector having a perpendicularly arranged socket. the conductor with the second measuring clamp is horizontally displaceable in the first and second tubes connected to the second connector.

The main advantage of the adapter according to the invention is the definition of additional measurement errors in that the wire-wound components to be measured can be directly inserted into the high-frequency line into the sliding measuring terminals, thereby reducing parasitic inductance and further eliminating phase calibration initial calibration errors. Another advantage is a quick check of the input side by connecting the calibration line to the measuring terminals.

The invention will be explained in more detail with reference to the accompanying drawing, in which: FIG. X and FIG. 3 show a diagram illustrating the nature of the measurements in FIG. 4; FIG. 4 is an axial section of an adapter; FIGS. 6 shows a calibration line conductor in the clamps, FIG. 7 shows a cross-section through a measuring clamp.

The adapter, as can be seen from FIG. 4, consists of a base body I. »which forms the external high-frequency conductor of the line (slab-line). In the Teflon dielectric 2, the circular center conductors 3, 4 are arranged, passing at an angle of 90 ° v to the measuring terminals 5 and 5. The first measuring terminal 5 is fixed and a socket 7 for insertion of the probe A is formed in its bend.

- 3 256 478 measuring instrument. The second measuring terminal 6 is displaceable and consists of three parts, the tubes 8 and 9 of the second measuring terminal 6 and the second circular center conductor 4. As the distance between the measuring terminals 5 and 6 increases, the second circular conductor 4 and the tubes 8, 9 slide into each other. It creates the maximum distance of the measuring terminals J5, 6 for connecting the measured object or the calibration line.

In order to ensure a quick and perfect connection of the measured component with the measuring terminals 5, 6, they are provided with springs 16,

17. The calibration line shown in FIG.

5a. 5b. which consists of a metal body 11 forming an outer circular conductor and S dielectrics 12 made of Teflon, in which a calibration center conductor 13 is placed at both ends, grinded into a strip for insertion into the measuring terminals 5i and Q. 14, 15 that engage a groove in the adapter body.

The component to be measured, as shown in FIG. 1, is connected in series with a resistive normal Zo of a known value, for example with a precision coaxial terminating resistor 50 [mu]. The measuring instrument records the voltages Ua and Ub before and after the component Z and the phases between them, the measured values and the known impedance Zo, we calculate the measured impedance Z of the component or directly the value of resistance, capacitance, inductance. In practical measurements, the distance between the measuring points (phase difference% distance of the measuring instrument probes) must be taken into account and subtracted from the measured phase as indicated in Figure 2. The resulting phase is given by the phase difference <x. The initial phase is determined during calibration by the calibration line. Measuring workplace with adapter shown on o.br. 3 forms an adapter C connected by a first connector to a high-frequency signal source G and a second connector to an adapter T, the output of which is connected to a resistive normal Zo. A measuring device M, for example a circuit analyzer, is connected to the adapter C by the probe A and the probe E> to the adapter T. The measured object Z is then between the measuring terminals 5, 6 of the adapter C.

256 478

Before the initial measurement, perform the calibration with the calibration line inserted on the measuring terminals J5, Q. Subtract the initial phase and, if measured with a hand-operated vector voltmeter, set the full deflection at the probe points A, B. Z, Subtract phase and high-frequency voltage U _{A in} front of the measured component (equals the full deflection set during calibration) and voltage υθ behind the measured object Z. From these measured values we calculate resistance, capacity or inductance of the measured object Z or its impedance or admittance and their phase angles.

Claims (1)

SUBJECT OF THE INVENTION Adapter for measuring resistances, inductances and capacities with sliding clamps and calibration lines, consisting of a basic cuboid body fitted with two coaxial center conductor connectors, characterized in that the two circular center conductors (3,4) mounted in the Teflon core (2) in the main body (1) extend at right angles to the front plane of the adapter and terminate with measuring clamps (5,6) provided with notches with two springs (16, 17), the first circular center conductor (3) with the first measuring clamp (5) being perpendicular an arranged socket (7) and connected to the first connector (10), while the second circular center conductor (4) with the second measuring clamp (6) is horizontally slidable in the first and second tubes (8,9) connected to the second connector (20),