Determination of changes of metrological characteristics of measuring instruments with time

1978 ◽  
Vol 21 (2) ◽  
pp. 158-163
Author(s):  
I. V. Abuladze ◽  
A. I. Belyaevskii ◽  
A. A. Dzhevdet
Keyword(s):  
Metrological Characteristics ◽  
Measuring Instruments

The Development of a Turbidimetric Method for the Quantitative Determination of Antibiotics of the Aminoglycoside Group in Medications

2020 ◽  
Vol 65 (7-8) ◽  
pp. 37-41
Author(s):  
E. N. Semenova ◽  
S. I. Kuleshova ◽  
E. I. Sakanyan
Keyword(s):  
Quantitative Determination ◽  
Quality Assessment ◽  
Aminoglycoside Antibiotics ◽  
Metrological Characteristics ◽  
Streptomycin Sulfate ◽  
Turbidimetric Method ◽  
Validation Criteria ◽  
Validation Parameters ◽  
Validation Tests

A method for the quantitative determination of streptomycin sulfate in medicines by the turbidimetric method has been developedand validated. Based on the results of the experiments, it was found that the metrological characteristics of such validation parameters of the method as linearity, precision, and correctness do not exceed the validation criteria. Linearity was noted in the range of streptomycin concentrations from 3.75 to 8.43 μg/ml. The results of validation tests of the method for the quantitative determination of streptomycin indicate the prospects and feasibility of introducing the turbidimetric method into the domestic system for standardization and quality assessment of aminoglycoside antibiotics.

METHOD FOR ESTIMATING ERRORS IN MEASURING INSTRUMENTS BY THE SPACE CATALOGUE ORBITS

2018 ◽  
pp. 76-84
Author(s):  
K. V. Sorokin ◽  
E. A. Sunarchina
Keyword(s):  
Dynamic Model ◽  
New Method ◽  
Measuring Instruments ◽  
Measuring Instrument ◽  
Software Complex

Improvement of orbits precision is one of the most important tasks of space surveillance catalogue maintenance. The solution of this problem is directly related to an adequate consideration of the errors of the coordinate information from the measuring instruments. The article consideresd a new method for estimating the precision of measuring instruments on the catalog orbits. To carry out such analysis, in PJSC «VIMPEL» special technological program was created. Main results of a study of radar errors with orbits of space surveillance catalogue was presented. Also, the results were compared with data of measuring instrument's calibration software complex. This software complex provides determination of satellite's position with errors less than 10 m. A new dynamic model of measuring instrument errors is proposed.

Determination of precision conditions for measuring relative values in mechanical tests of various materials

2021 ◽  
pp. 9-17
Author(s):  
Svetlana Yu. Lohanina ◽  
Olga V. Baranova ◽  
Larisa V. Trubacheva
Keyword(s):  
Wear Resistance ◽  
Mechanical Testing ◽  
Mechanical Tests ◽  
Metrological Characteristics ◽  
Measuring Instruments ◽  
Quantitative Chemical Analysis ◽  
Uniformity Of Measurements ◽  
Multi Stage ◽  
Abrasive Disk ◽  
Accuracy Of Measurements

The problem of insufficient detail of the requirements for the developed and certified measurement methods used in mechanical testing of various materials is considered. The compatibility of the requirements of metrological support for the results of quantitative chemical analysis and indirect results of mechanical tests for the wear resistance of materials when rubbing against a fixed abrasive is relevant. To ensure the accuracy of measurements, it is proposed to use the grain size of the abrasive material and the rotation speed of the abrasive disk as variable factors. In order to establish the requirements for the metrological characteristics of materials during mechanical tests, in particular, when determining the relative wear resistance, the conditions for precision measurements are justified. The results of a multi-stage experiment-testing of materials for wear resistance with the use of various research and consumables, measuring instruments and testing equipment are presented. The conditions for the organization of the experiment in the case of determining other relative mechanical characteristics of the materials under study for establishing precision indicators in the development of methods of mechanical tests for abrasive wear are proposed and justified. The application of the obtained results will allow developers of mechanical testing methods to establish metrological characteristics of materials in compliance with all the requirements of the State System for Ensuring the Uniformity of Measurements of the Russian Federation.

Исследование градуировочной характеристики турбинных преобразователей расхода жидкости типа MVTM

2021 ◽  
pp. 576-581
Author(s):  
Petr S. Gulyaev ◽  
Alexander N. Teplykh ◽  
Andrey Y. Dyachenko
Keyword(s):  
Calibration Curve ◽  
Conversion Factor ◽  
Oil Quality ◽  
Pulse Frequency ◽  
High Viscosity ◽  
Metrological Characteristics ◽  
Metrological Reliability ◽  
Oil Viscosity ◽  
Piecewise Parabolic

Most of the failures of turbine flow converters (TFC) used in the Russian system of main oil pipelines and oil product pipelines are caused by abrupt changes in the viscosity of the transported medium. In studies related to determination of the influence of the rheological properties of the pumped oil on the metrological characteristics of TFC that have a calibration curve in the form of a piecewise approximation without taking into account the correlation of TFC rotor speed with the viscosity of the pumped liquid in the flow rate subrange, the instability of the metrological characteristics in the operating range is observed. Taking into account the tendency to increase the volume of production and pumping of high-viscosity oils it can be assumed that the irregularity of the metrological characteristics of TFC, expressed in the change in the conversion factor will remain, which will negatively affect the reliability of accounting operations using oil quality control system (OQCS). Accordingly there is a need to maintain the error of TFC within the set limits in the subranges and throughout the entire range of flow rates. According to the results of the study performed by the authors it was confirmed that for the TFC of MVTM type the use of the calibration curve in the form of a piecewise-parabolic approximation with the dependence of the conversion factor on the ratio of TFC pulse frequency to the oil viscosity makes it possible to minimize the effect of changes in the parameters of the pumped medium on the measurement accuracy and as a consequence to stabilize the metrological characteristics of TFC in the recalibration interval, eliminate the costs of performing out-of-turn verifications, increase the accuracy and metrological reliability of the OQCS. Большинство отказов турбинных преобразователей расхода (ТПР), используемых в российской системе магистральных нефтепроводов и нефтепродуктопроводов, обусловлено резкими изменениями вязкости транспортируемой среды. В исследованиях по определению влияния реологических свойств перекачиваемой нефти на метрологические характеристики ТПР, имеющих градуировочную характеристику в виде кусочно-линейной аппроксимации без учета корреляции частоты вращения ротора ТПР с вязкостью перекачиваемой жидкости в поддиапазоне расхода, отмечается нестабильность метрологических характеристик в рабочем диапазоне. Учитывая тенденцию увеличения объема добычи и перекачки высоковязких нефтей, можно предположить, что непостоянность метрологических характеристик ТПР, выражаемая в изменении коэффициента преобразования, сохранится, что негативно скажется на достоверности учетных операций с применением систем измерений количества и показателей качества нефти (СИКН). Соответственно, возникает потребность в поддержании погрешности ТПР в установленных пределах в поддиапазонах и во всем диапазоне расходов. По результатам проведенного авторами исследования подтверждено, что для ТПР типа MVTM использование градуировочной характеристики в виде кусочно-параболической аппроксимации с зависимостью коэффициента преобразования от отношения частоты импульсов ТПР к вязкости нефти позволяет минимизировать влияние изменений параметров перекачиваемой среды на точность измерений и, как следствие, стабилизировать метрологические характеристики ТПР в межповерочном интервале, исключить затраты на выполнение внеочередных поверок, повысить точность и метрологическую надежность СИКН.

scholarly journals Tropospheric nitrogen dioxide column retrieval from ground-based zenith–sky DOAS observations

2015 ◽  
Vol 8 (6) ◽  
pp. 2417-2435 ◽  
Author(s):  
F. Tack ◽  
F. Hendrick ◽  
F. Goutail ◽  
C. Fayt ◽  
A. Merlaud ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Atmospheric Composition ◽  
Optical Absorption Spectroscopy ◽  
Retrieval Algorithm ◽  
Measuring Instruments ◽  
Reference Spectrum ◽  
Vertical Column ◽  
Data Set ◽  
Residual Amount

Abstract. We present an algorithm for retrieving tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs) from ground-based zenith–sky (ZS) measurements of scattered sunlight. The method is based on a four-step approach consisting of (1) the differential optical absorption spectroscopy (DOAS) analysis of ZS radiance spectra using a fixed reference spectrum corresponding to low NO2 absorption, (2) the determination of the residual amount in the reference spectrum using a Langley-plot-type method, (3) the removal of the stratospheric content from the daytime total measured slant column based on stratospheric VCDs measured at sunrise and sunset, and simulation of the rapid NO2 diurnal variation, (4) the retrieval of tropospheric VCDs by dividing the resulting tropospheric slant columns by appropriate air mass factors (AMFs). These steps are fully characterized and recommendations are given for each of them. The retrieval algorithm is applied on a ZS data set acquired with a multi-axis (MAX-) DOAS instrument during the Cabauw (51.97° N, 4.93° E, sea level) Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI) held from 10 June to 21 July 2009 in the Netherlands. A median value of 7.9 × 1015 molec cm−2 is found for the retrieved tropospheric NO2 VCDs, with maxima up to 6.0 × 1016 molec cm−2. The error budget assessment indicates that the overall error σTVCD on the column values is less than 28%. In the case of low tropospheric contribution, σTVCD is estimated to be around 39% and is dominated by uncertainties in the determination of the residual amount in the reference spectrum. For strong tropospheric pollution events, σTVCD drops to approximately 22% with the largest uncertainties on the determination of the stratospheric NO2 abundance and tropospheric AMFs. The tropospheric VCD amounts derived from ZS observations are compared to VCDs retrieved from off-axis and direct-sun measurements of the same MAX-DOAS instrument as well as to data from a co-located Système d'Analyse par Observations Zénithales (SAOZ) spectrometer. The retrieved tropospheric VCDs are in good agreement with the different data sets with correlation coefficients and slopes close to or larger than 0.9. The potential of the presented ZS retrieval algorithm is further demonstrated by its successful application on a 2-year data set, acquired at the NDACC (Network for the Detection of Atmospheric Composition Change) station Observatoire de Haute Provence (OHP; Southern France).

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