Calibrator


Also found in: Dictionary, Thesaurus, Medical, Legal.

Calibrator

 

in electrical and radio engineering, a precision device for tuning and calibration of measuring instruments (determination of errors or correction of scale values). Its operation is based on comparison to a standard of the value being measured.

Calibration generators operating on several strictly defined frequencies from 100 hertz (Hz) to 100 megahertz (MHz) are usually used for frequency calibration of frequency meters, standard-signal generators, radio reception and transmission equipment, and other instruments with a continuously variable tuning range. Electrical oscillations are supplied by a piezoelec-trically stabilized generator with a relative frequency error of up to ±1 × 10”-5. In addition to the fundamental frequencies, harmonics of the fundamental frequencies in the range of 20-40 gigahertz (GHz) are also used. In a continuous frequency range heterodyne frequency meters are also used for this purpose. A calibrating generator usually consists of a reference crystal oscillator, a frequency converter, a mixer-detector, and an audiofrequency amplifier, which make possible calibration without any additional apparatus. The principle of operation of a calibrator is based on a comparison of the frequency being measured with the fundamental frequency (or one of its harmonics) of a crystal oscillator and separation of the difference frequency by the zero-beat method in a mixer-detector.

Frequency standards are calibrated by means of receiver comparators according to the signals of radio stations transmitting on superlong wavelengths. Under certain conditions of propagation of long waves (a = 10, 000 m), phase stability over a 24-hour period makes possible highly precise comparison of the frequency of the signals received to standard frequencies. In 1970 there were seven radio stations that regularly transmitted signals of great frequency precision. Their signals could be received throughout the world. Calibrators also exist for checking the voltage indicated by electron-tube voltmeters; they are called calibration voltage sources (for direct and alternating current).

Calibrators are also used for precision work in metrology, for measuring sets of standards, and for calibrating instrument scales. Calibration should not be confused with graduation, which is a metrological operation that consists in the division of an instrument scale into units established for it.

REFERENCES

Malikov, M. F. Osnovy metrologii, part 1. Moscow, 1949.
Izmereniia v elektrotekhnike: Spravochnik, vol. 1. Compiled by B.A. Dobrokhotov. Moscow-Leningrad, 1965.
Shkurin, G. P. Spravochnik po elektroizmeritel’nym i radioizmerit’nym priboram, 3rd ed., vols. 1-2. Moscow, 1960.

V. V. BOGOMAZOV

References in periodicals archive ?
However, Siemens reagents, calibrator, and instrument systems that are distributed outside the United States have reportedly been recalibrated to yield ERM-DA471/IFCC-traceable results.
Environmental Protection Agency (EPA] regulations can now rely on enhanced mercury calibrators to speed compliance with the new regulatory requirements of individual facilities.
If the difference exceeds the criterion, the calibrator set is rejected.
Usually, several calibrators are used in series, separated by relatively short air zones (7, 8), where the temperature tends to equalize, to minimize the internal thermal induced stresses and increase the heat transfer efficiency in the next calibrator.
A In theory, any manufacturer's calibrator can be used with your Olympus analyzer.
In order to calibrate resistance thermometers, thermocouples or temperature transmitters, it is possible to integrate an electrical measuring instrument into the calibrator as an option.
Home Value Calibrator automatically analyzes home valuation data and provides a score to indicate if there are valuation inconsistencies in neighborhoods with recent home sales.
6 GHz calibrator is identical to that of the 24 GHz calibrator, but is software driven.
Model CAL10 Thermocouple Calibrator calibrates electronic process equipment such as controllers, transmitters and recorders.
In addition the monitors can be enhanced with the optional USB blue eye hardware calibrator which allows users to adjust each electron gun in the monitor individually until the optimum settings are achieved.
announcedtoday that it has commercially launched the ARQ IS Calibrator Panels (RUO*), intended to aid laboratories with standardization of BCR-ABL1 quantitative measurements on the International Scale (IS).