Annotation: The effective documents in the field of metrological support require evaluating measurement uncertainty during measuring instrumentation calibration. In Ukraine, there is no regulated procedure of uncertainty calculation during measuring instrumentation calibration, which causes the necessity of developing such procedure. This article proposes the measurement uncertainty calculation procedure during measuring instrumentation calibration, according to which the following calculations shall be made: a) of standard uncertainty of A type for corrected observation results obtained during calibration; b) of standard uncertainties of B type caused by error or uncertainty of working standard applied, calculation discreteness or calibrated measuring instrument division value, variation of calibrated measuring instrument indications; c) of total standard measurement uncertainty; d) of augmented measurement uncertainty. As an example, the results of calculation of augmented measurement uncertainty during calibration are presented: – for 795M107B vibrometer in complete set with AC102-1A accelerometer; – for alternating voltage measurement channel of a measuring and computing complex of MIC type; – for a manometer of MT type. The obtained results of measurement uncertainty calculation are presented in the form of tables of measurement uncertainty budget, which shall be entered in the measuring instrument calibration certificate together with the observation results obtained during calibration. The proposed uncertainty calculation procedure is applicable for the given types of measuring instruments whose calibration is performed by method of direct measurement of known measurement values represented or controlled by working standards.

Annotation: The measurement errors upon conducting flight tests for launch vehicles are evaluated by considering the interferences and uncertainties in the measurement system procedure. Formal use of this approach can lead to unpredictable consequences. More reliable evaluation of errors upon conducted measurements can be achieved if the measurement process is regarded as a procedure of successive activities for designing, manufacturing, and testing the measurement system and the rocket including measurements and their processing during the after-flight analysis of the received data. The sampling rates of the main controlled parameters are three to ten times higher than the frequency range of their changing. Therefore, it is possible to determine the characteristics of the random error components directly on the basis of registered data. The unrevealed systematic components create the basic uncertainty in the evaluation of the examined parameter’s total measurement error. To evaluate the precision and measurement accuracy of a particular launch, the article suggests specifying the preliminary data on measurement error components determined during prelaunch processing and launch. Basic structures of algorithms for evaluation of precision and measurement accuracy for certain mathematical models that form the measured parameters were considered along with the practical case when static correlation existed among the measured parameters.

Annotation: At Yuzhnoye State Design Office, the Cyclone-4 launch vehicle 3rd stage engine has been developed and is under testing. For adjustment of the engine and test bench systems, in the first firing tests the radiation-cooled nozzle extension was replaced with a steel water-cooled one. It was planned to start the engine with water-cooled nozzle extension without vacuumizing and without gad dynamic pipe, which conditioned operation with flow separation at the output edge of water-cooled nozzle extension. Therefore, the calculation of flow in the nozzle with water-cooled extension, flow separation place, and thermal load on watercooled nozzle extension during operation in ground conditions is an important task. Selection of turbulent flow model has a noticeable impact on prediction of flow characteristics. The gas dynamic analysis of the nozzle with water-cooled extension showed the importance of using the turbulent flow model k-ω SST for the flows with internal separation of boundary layer and with flow separation at nozzle section. The use the flow model k-ω SST for calculation of nozzle with flow separation or with internal transitional layer allows adequately describing the flow pattern, though, as the comparison with experimental data showed, this model predicts later flow separation from the wall than that obtained in the tests. The calculation allows obtaining a temperature profile of the wall and providing the recommendations for selection of pressure measurement place in the nozzle extension for the purpose of reducing sensors indication error. With consideration for the special nature of the nozzle extension wall temperature field, the cooling mode was selected. The tests of RD861K engine nozzle with water-cooled extension allow speaking about its successful use as a required element for testing engine start and operation in ground conditions without additional test bench equipment.

Annotation: The paper deals with the options of solving the task of constructing an inertial navigation system in the conditions of considerable g-load and angular velocity in identified direction by method of setting the sensitive elements at some angle to the identified direction, which allows making measurements in it without loss of measurement quality in the other directions. The paper describes the technique of calculating the angle of sensitive elements setting to the identified direction. The scheme of constructing an inertial navigation system with incomplete set of sensitive elements is considered for the cases when in entire operation leg, rotation around the identified direction is executed. The analysis is given of measurement vector error due to incompleteness of the sensitive elements set.

Annotation: The description of the program and its work on the part of the user is given as well as a description of the software automation solution from the programmer’s side. The introduction of an automated program has significantly accelerated the process of attestation of climatic chambers.

Annotation: Example of the estimate of the measurement error of the linear accelerations during the free fall of the kinematic model is considered. It was concluded that experiments on error measurements can be replaced with calculations for those parameters which have sufficient initial data on metrological performance of the applied instrumentation.

Annotation: Applicable documents on metrological assurance regulate the estimation of measurement uncertainty. In Ukraine there is no regulative methodology for uncertainty calculation when certificating test equipment that causes the necessity of its definition. This article offers the methodology for uncertainty calculation when certificating a centrifugal machine that is used to reproduce precisely the given value of linear acceleration that permanently acts on a tested unit spinning together with a rotor. The offered methodology for uncertainty calculation is applicable to centrifugal machines, for which numerical values of reproducible linear acceleration are determined by results of calculations of the centrifugal machine’s rotor angular velocity and radial distance from rotor’s longitudinal axis to the given point of the tested unit. Initial data used were results of observation obtained after multiple reproductions of the given values of linear acceleration as well as numerical values of errors and measurement uncertainties of measuring equipment that was used when monitoring the rotary angular velocity and radial distance considering the contribution of each measurable parameter to a certain value of linear acceleration. The calculation given in the article estimates the limit of linear accelerations that can be attributed with established probability to the given value of linear acceleration reproduced when certificating the centrifugal machine. The design formulae are given to estimate the uncertainty components of the reproducible values of linear accelerations and the recommendations are given to present the uncertainty budget.

Annotation: The solid rocket motors thrust is measured according to the developed measurement procedure; fulfilment of its requirements guarantees obtaining the results with required accuracy parameters. Compliance of this procedure with the measurement accuracy requirements is confirmed by way of its validation that can be performed according to different algorithms. The proposed article deals with two validation algorithms of measurement procedure for solid rocket motor thrust up to 30 tf – end-to-end and link-by-link validation methods. The composition of measurement channel, the experimental works performed at each validation algorithm are described, the calculation formulas to evaluate the limits of absolute measurement error and the obtained numerical values of the latter are presented. The comparative analysis of the results of validation procedure of solid rocket motor thrust measurement procedure obtained during metrological investigations of thrust measurement channel by end-to-end and link-by-link validation methods shows that to ensure the required measurement accuracy, the algorithms of end-to-end method is preferable, at which the lower values of reduced error can be obtained as compared with the algorithm of link-by-link validation.