The impedance measurement is completed by vector voltage method,including the technologies of testing impedance using auto-balance bridge,10 kHz～5 MHz frequency synthesis,phasicdetection and dual-integral A/D transforming.

In the designed hardware, AT89C51 single chip computer and many kinds of new type circuit chip (including: special power measuring chip-CS5460A, DS1302 calendar/clock chip, SMS0601 LCD, X5045 serial memory) are used for design. The hardware circuit is simplified, the meter's anti-interference ability is enhanced and the precision of measurement is also advanced.

A series of experiments show that the uncertainty of this multiplier for power measurement is less than 1×10-3 at a power factor of 0.1 and within a frequency range of 40Hz to 3.1kHz.

The network based measurement is a new direction of the measuring technology of mechanical parameters, and the virtual instrument is the base of network based measurement.

Direct current is widely applied on subway, electric railway and metalsmelt. The direct current measurement is also an important part ofelectromagnetic measurement.

Transformer's DC resistance measurement is one of the primary item before transformer leaving factory and precautionary test. The inherent time constant of transformer is quite long, so it is very important to study how to shorten the measuring time.

Harmonic measurement is an important embranchment of harmonic problem. It is not only the main basis of studying the harmonic problem, but also the starting point of analyzing the problem.

When we measure the amount of partial discharge, the accuracy of measurement is varied constantly by outer interference, it's important to distinguish partial discharge pulse from interference pulse, so how to judge insulation quality according to partial discharge information became the study direction of many scholars and site personnel.

In chapter two^ three and four, the new measurement is elaborated in the principle of graphic analysis and site application. In the end ,the author summarized, and out looked the future.

An effective approach combining theoretical analysis and mathematical calculations with experimental measurement is presented in this paper to determine the grinding area and allowance for compensating the boresight error performance of the radome.

Compared with the method via non-modulated electron beams, the instrument of measurement is simplified.

It is predicted that the superposition persistence time will increase if the measurement is carried out with a low accuracy and a minimum variance.

A method of SEM linear measurement is proposed in which the reference marker displayed on the screen is used as a standard.

The sensitivity of this method can be high because frequency measurement is one of the most accurate measurements in physics and metrology.

This paper presents a method of determining the actual average temperature rise of the stator winding of a high-voltage a.c. machine, by measurig-the resistance of that winding under load by means of Kelvin bridge. The method discussed herein has the following special features:1) The installation for measurement is at zero potential, so that safety is assured in operation,2) By taking appropriate measures, disturbance of the a.c. components is Kept away from the bridge circuit, so that the installation...

This paper presents a method of determining the actual average temperature rise of the stator winding of a high-voltage a.c. machine, by measurig-the resistance of that winding under load by means of Kelvin bridge. The method discussed herein has the following special features:1) The installation for measurement is at zero potential, so that safety is assured in operation,2) By taking appropriate measures, disturbance of the a.c. components is Kept away from the bridge circuit, so that the installation of a complicated filter in the galvanometer circuit can he omitted. While the galvanometer still operates steadily.3) A unified method for choosing measuring elements can he applied to various ratings of machines.4) High accuracy of measurement is assured. The maximum error of resistance measurement is within 0.3%, if proper measuring elements were chosen.In the paper the result of measurement and its error are analyzed.

A method for the measurement of short-circuit high current with a magnetic potentiometer of high precision and electronic integrator is recommended for use in industry.In this paper the measuring principle and the frequency response of the magnetic potentiometer and electronic integrator as well as data selection and error analysis are described.The accuracy of this method is 1 % and the range of measurement is over 102-105 V.

The measurement of HF parameters of capacitors by the transmission method is discussed here in detail. We have proposed and investigated a transmission system. By using the lumped impedance power distributor and RF vector voltmeter, the impedence-frequency characteristics of fixed capacitors can be measured easily in the freqency range up to 1000MHz. The system is also applicable, if necessary to even wider range of measurement. The selfinductance of capacitors can be measured down to 10~(-4) μHz, and the equivalent...

The measurement of HF parameters of capacitors by the transmission method is discussed here in detail. We have proposed and investigated a transmission system. By using the lumped impedance power distributor and RF vector voltmeter, the impedence-frequency characteristics of fixed capacitors can be measured easily in the freqency range up to 1000MHz. The system is also applicable, if necessary to even wider range of measurement. The selfinductance of capacitors can be measured down to 10~(-4) μHz, and the equivalent series resistance of capacitors can be measured down to 10~(-2) Ω. The method is simple and effective, and the accuracy of measurement is good for practical purpose. The method proposed has already been adopted as a standard method in the country.