Calibration and measurement certified capabilities of the Russian Federation included in the international database in the area of analytic chemical measurements

The organizational principles of the international system of uniformity of analytic chemical measurements implemented by the International Bureau of Weights and Measures and the Consultative Committee on Quantity of a Material – Metrology in Chemistry are described. The degree of participation of Russian metrological institutes in the implementation of the international agreement on mutual recognition of national standards and calibration certificates is considered. An estimate of the level of measurement and calibration capabilities of Russian metrological institutes is presented.     

AC power & energy standard — NPLI measurement, calibration & testing

AC power & energy standard of National Physical Laboratory, India (NPLI) is responsible for maintenance of national measurement standard of ac power & energy and international traceability through intercomparisons. It serves as the basis for dissemination of traceability in measurement through high level calibration and measurement services to the various user organizations in the country. It also supports and helps the industries in improving the measurement assurance systems through interlaboratory proficiency testing (PT) program and in solving actual field problems. Power measurement at zero power factors using zero power factor standards is described as it is used in intercomparison. The performance of energy meters under the various influence quantities is described as a service to the industries.     

Stability evaluation of high-precision multifunction instrumentsfor traceability transfer

In the traceability transfer process from the national standards of the Istituto Elettrotecnico Nazionale “Galileo Ferraris” to standards of calibration laboratories accredited by Servizio di Taratura in Italia, the use of high-precision multifunction instruments, in particular digital multimeters, as reference standards turned out to be a good transfer method. In fact, their use provides swift and less expensive transfer at an uncertainty level comparable to that one obtained using high-precision individual standards, such as 10 V DC voltage standards, standard resistors, or AC/DC transfer standards. In this paper, how this transfer process is performed and what results are obtained, are described     

Construction of calibration curves for methods of analyzing environmental samples

A formalized procedure is proposed for constructing calibration curves and evaluating their error in methods developed for the quantitative chemical analysis of environmental samples. The procedure satisfies the requirements of government metrological standards. Examples from practice are given to illustrate the construction of linear and nonlinear calibration curves and the corresponding confidence intervals. Translated from Izmeritel'naya Tekhnika, No. 3, pp. 64–68, March, 1998.     

Comparing hydrophone calibration results for Russian and Chinese standards

Russian and Chinese national standards have been compared by exchanging hydrophones for calibration in the frequency range from 1 Hz to 630 kHz. The results agree very closely, which confirms that the estimates made of the errors in the two standards are reliable. Deceased. Translated from Izmeritel'naya Tekhnika, No. 6, pp. 63–67, June, 2000.     

The Humidity Calibration Facility of the National Metrology Institute of South Africa (NMISA)

The NMISA Humidity Laboratory maintains the South African national measurement standards for humidity and provides traceability for commercial calibration laboratories. The laboratory performs both relative humidity and dew-point calibrations. The laboratory has been accredited since January 2004 for both parameters by the South African National Accreditation System (SANAS). Industries such as the pharmaceutical industry, power stations, and the food industry make use of the calibration services provided by the laboratory. The facilities and the measurement capabilities of the laboratory are presented in this paper. Two calibration methods are used for the calibration of relative humidity measuring instruments (RH meters). Depending on the type of instrument, they are calibrated against aqueous salt solutions or by comparison with reference RH meters. Measurements are performed over the humidity range 5–95 %rh (Best Measurement Capabilities: 0.4–1.4 %rh). Two chilled-mirror hygrometers are used as reference standards for dew-point calibrations over the range from −75°Cfp to +17°Cdp (Best Measurement Capabilities: 1.5°Cdp to 0.4°Cdp). The laboratory has participated in two international interlaboratory comparisons, one for each accredited parameter. The NMISA Humidity Laboratory is working to reduce its calibration uncertainties for relative humidity instruments: since first accredited in 2004, the best measurement capabilities have been improved from 2.1 %rh to 0.4 %rh for some humidity ranges.     

State primary special standard and standard samples for support of the uniformity of measurements of the surface density of coatings

This is an analysis of the state of and prospects for metrological support in the area of measuring the surface density of coatings based on the state primary special standard GET 168-2010. The basic characteristics of the standard and its components are discussed. The verification procedure based on this standard and regulated by the standards document GOST R 8.612–2005 is described. The role of standard samples of coating surface density and their place in the testing, verification, and calibration of devices for measuring the thickness of coatings and comparisons with the standard is pointed out in order to confirm its measurement and calibration capabilities.     

Modified Calibration Coefficients of Two-Port CPW Standards with Superstrate Effects

Calibration standards are used for the calibration of a vector network analyzer to characterize the microwave components under test. For the direct characterization of coplanar waveguide components, two-port CPW open, short and line are proposed to complement the existing calibration techniques. The developed CPW standards are characterized in the frequency range of 10 MHz to 10 GHz. As these are planar structures, effects of small superstrates on the calibration coefficients of open and short are studied also. The CPW line has shown slight changes in impedance due to superstrates, whereas a few calibration coefficients of open and short standards showed dependence on superstrates. Similar observations are noted by improving the polynomial models of CPW open and short standards up to fifth and sixth order, respectively, which better matches for CPW standards. The reported results are helpful to estimate any change in the measurement uncertainty on using such calibration standards due to superstrates.     

Improvement of the standard of the unit of sound pressure in an aqueous medium

Basic historical information regarding the time and location when standards of sound pressure in an aqueous medium were set up are presented. The development of the technical and metrological characteristics of the standard is described. The results of comparisons of the state standards of sound pressure with the national standards of the leading countries of the world are discussed. __________ Translated from Izmeritel’naya Tekhnika, No. 12, pp. 49–52, December, 2007.     

静水压测试仪校准方法探讨

通过对适用领域、相应国家标准和技术参数的分析,介绍两种静水压测试仪的异同;同时基于以上分析,探讨静水压测试仪器校准时标准器的选择和校准方法,以及校准过程中可能遇到的问题和需要注意并采取的办法。     

Metrological base of the Siberian research institute of metrology (SNIIM) in the area of measuring the parameters of alternating current electrical circuits

This paper describes the major milestones in the development of precision measurements of electrical circuit parameters at frequencies of 1 kHz – 300 MHz from the 1950s to the present day. Work on the creation of national standards in this area, as well as of working standards for electrical units, is described. Future developments are discussed.     

Design and metrological applications of a low noise, high electrical isolation measurement unit

A digitally controlled voltage generation and measurement unit optimised for high-precision electrical metrology is described. It is optically isolated from the controlling computer and contains specially constructed isolated power supplies allowing continuous operation without the need to recharge batteries. The source has a simple microcontroller that is pre-programmed with firmware to control operation and to carry out simple repetitive measurement tasks, such as generation and quantisation of signals using uniform sampling. The merits of the developed unit are demonstrated by three example applications: (i) the application of the unit to control a Josephson voltage standard, (ii) the implementation of a transfer standard for the calibration of the electronic instrumentation of fatigue testing machines traceable to the primary electrical standards and (iii) the force measurement of an ion thruster traceable to the primary electrical standards at the industrial user level.     

Conversion of methane to hydrogen in a reversible flow superadiabatic inert porous medium reactor

Using the analysis of the experimental data on partial oxidation of methane as an example, we have shown that the chemical processes in the inert medium of a reciprocating flow reactor can be modeled with good accuracy by the standard kinetic scheme for homogeneous processes due to the fact that the gas flow in the region of combustion is described by two temperatures — the gas and framework temperatures. Such a modification of the chemical model requires neither changing the recognized mechanism of homogeneous chemistry nor correcting the volume heat transfer coefficient.     

Improved method of calibration of working standards of the amplitude modulation index

A new method of indirect calibration of working standards of amplitude modulation of the 1st class based on the K2-34 setup is described. Calibration is carried out with the aid of working standards of power, voltage, and nonlinear distorition factor adopted from other calibration schemes. Translated from Izmeritel'naya Tekhnika, No. 11, pp. 53–56, November, 1997.     

Upgradation of a spectral irradiance measurement facility at National Physical Laboratory,India

This report describes the details of a recently upgraded spectral irradiance measurement facility in optical radiation standards at National Physical Laboratory, India. This facility provides the calibration of spectral irradiance in the wavelength range 280 nm – 2500 nm. PTB, Braunschweig, Germany calibrated five numbers of 1000 W quartz halogen lamps, which are used as reference standards for spectral irradiance scale. In addition to providing the details of instruments, the procedure of calibration and evaluation of uncertainties is also described. For checking the fidelity, repeatability and reproducibility of the upgraded system, calibration of one of the PTB calibrated lamps, was done against the other four PTB calibrated lamps. These measurements not only provide confidence on the upgraded system but also verify the retention of the PTB certificate values after a lapse of two years after their calibration.     

Metrological traceability chain for pH measurement results

The extent to which technical barriers to international trade caused by non-acceptance of chemical measurement results can be removed, largely depends on the success in building up national and international traceability structures also in metrology in chemistry. Achieving metrological comparability of measurement results requires the definition of metrological calibration hierarchies providing metrological traceability chains which enable the establishment of metrological traceability of measured quantity values to a common metrological reference [1]. For pH, over the last decade, work has been carried out in a number of countries to build up meteorological calibration hierarchies within a national framework. An overview on the metrological traceability chain for pH is given with focus on the primary measurement procedure of pH.     

The NIST Primary Radon-222 Measurement System

Within the United States, the national standard for radon measurements is embodied in a primary radon measurement system that has been maintained for over 50 years to accurately measure radon (²²²Rn) against international and national radium (²²⁶Ra) standards. In turn, all of the radon measurements made at the National Institute of Standards and Technology (NIST) and the radon transfer calibration standards and calibration services provided by NIST are directly related to this national radon standard. This primary radon measurement system consists of pulse ionization chambers and ancillary gas handling and gas purification equipment. The system is currently undergoing a significant upgrading and expansion which will replace the extant outdated system.     

Unified Measurements of Quantities Characterizing Incoherent Optical Radiation

A suite of state primary standards is described for the units of optical radiation consisting of precision standard sources, detectors, and other opticoelectronic devices developed at VNIIOFI in the period 1982–2002. Results are given from international comparisons and the use of standard facilities and calibration units for metrological support to space research and remote Earth sensing. __________ Translated from Izmeritel'naya Tekhnika, No. 11, pp. 12–16, November, 2005.     

Accuracy in Image Evaluation: Setting up an OTF Standards Laboratory

In 1966 the British Calibration Service was set up to operate a nation-wide measurement scheme which includes the calibration of optical equipment. Under this scheme, industrial and other laboratories may apply for approval to issue official calibration certificates covering the measurement of optical transfer functions, and the OTF laboratory at the Royal Aircraft Establishment is being organized, in collaboration with the National Physical Laboratory, as the national standards centre to which such measurements can be referred. This work has led to a critical study of the sources of error in OTF measurement, and the main features of this study are described here.