Development of a generalized mathematical model of static error electromechanical measuring equipment

To keep military equipment fit for use, carry out maintenance activities, an important and integral part of which is metrological service. The effectiveness of metrological services depends on the completeness of the coverage of the monitored parameters, frequency and reliability of their measuring control. The most common, at present, when controlling the parameters of military equipment are electromechanical measuring equipment. The main metrological characteristic of electromechanical measuring instruments in a static measurement mode is the nominal calibration characteristic. During operation, the calibration characteristic of electromechanical measuring instruments, under the influence of various factors, has deviations from the nominal, which leads to an instrumental static error. The article deals with the applied aspects of assessing the static error of electromechanical measuring equipment, which is expressed through the sensitivity or static transmission coefficients of measuring transducers. Based on the results of the analysis, a generalized mathematical model of the relative static error of electromechanical measuring equipment for various structural schemes of connecting measuring transducers was obtained. It is proposed to apply a generalized mathematical model to assess the relative static error of electromechanical measuring instruments (with various structural schemes) during their operation. The use of an updated static error will allow to refine the calibration characteristics of electromechanical measuring instruments, which in turn will lead to obtaining reliable information about the state of military equipment during metrological maintenance and immediately before use.

RESULTS OF MILKING INSTALLATION TESTER TEST V. 2.0

The process of diagnosis of milking parlors should be carried out using measuring instruments. Measuring instruments must have a maximum error which together with the statistical error of measurements guarantees that according to the requirements of ISO 5707: 2007 the data can be recorded with sufficient accuracy. Instruments must be calibrated regularly to ensure the required measurement accuracy (ISO 6690: 2007). Developed Milking machine tester v. 2.0, which consists of an automated control system with the ability to connect additional external sensors (air flow, temperature and Hall sensors), two built-in pressure sensors (based on MPX 5100DP) and batteries. The automated control system is made on the basis of the Arduino Mega 2560 hardware platform with the control keyboard and the graphic display 3.2 "320 × 480 TFT LCD. The purpose of researches is to carry out calibration of experimental sample Tester of milking installations v. 2.0 As a result of calibration of the pressure sensor included in the Tester of milking installations v. 2.0, the following was established: the calibration characteristic of the sensor is linear in the investigated pressure range (4.75-62.00 kPa); the equation describing the calibration characteristic coincides with the equation given in the technical documentation for the sensor, the error of measuring the pressure in the specified range is about 1 kPa, the calibration results do not suggest that the pressure sensor has a hysteresis effect. found that the determination of the duration of the pulse phases is characterized by a resolution of 19.70 ms and a measurement error of ± 31 ms in the frequency range of pulsations 37.3-131.0 pulses/min The magnitude of this error does not depend on the pulsation frequency in the specified range.

Determination of the mass concentration of benzoic acid in non-alcoholic and low-alcohol products by the spectrophotometric method

In the production of low-alcohol and non-alcoholic beverages, the use of preservatives is allowed, including benzoic acid (BК) and its salts. Standard methods based on high performance liquid chromatography are used to control the content of this preservative. This work presents the results on the determination of benzoic acid in samples of low-alcohol and non-alcoholic products by the spectrophotometric method. Research has been carried out to establish the optimal wavelength when measuring the optical density of benzoic acid solutions. A calibration characteristic has been constructed to determine the mass concentration of benzoic acid, which makes it possible to determine its concentration in the range from 10 mg/dm3 to 500 mg/dm3 of benzoic acid, taking into account dilution. Metrological data have been obtained for constructing a calibration characteristic for the determination of benzoic acid in low-alcohol and non-alcoholic products. It is shown that the results of the determination of this preservative in the indicated products by the spectrophotometric method are comparable with the analogous results obtained using standard methods based on high performance liquid chromatography. The research results became the basis for the developed Methodology for measuring the mass concentration of sorbic and benzoic acids in low-alcohol and non-alcoholic products by the spectrophotometric method. The developed technique allows measuring the mass concentration of benzoic acid in low-alcohol and non-alcoholic products containing only benzoic acid. The spectrophotometric method for determining the mass concentration of BA is a less costly method for determining this preservative in a product than the currently used method of high-performance liquid chromatography, does not require special expensive equipment, additional consumables and specially trained personnel..

Calibration of the loop probe for the near-field measurement

Accurate near-field measurements for either deterministic or stochastic electromagnetic fields characterization require a relevant process that removes the influence of the probes, transmission lines, and measurement circuits. The main part of the experimental work presented here is related to a calibration procedure of a test setup consisting of a microstrip test structure and a scanning loop probe. The calibration characteristic, obtained by comparing measured and simulated results, is then used to convert the measured voltage into the magnetic field across and along the microstrip line at the specific height above it. By performing the measurements and simulations of the same test structure with the loop probe in the presence of an additional scanning probe, the influence of the additional probe to the measured output is thoroughly investigated and relevant corrections are given. These corrections can be important when two-point correlation measurement is required, especially in scanning points when two probes are mutually close.

PHYSICAL-MATHEMATICAL MODEL OF BENDING FIBER-OPTIC SENSOR OF FORCE

There is presented a model of an explosion-proof, jam-resistant under conditions of high level electromagnetic fields fiber-optical sensor of tensile force on the basis of a fiber-optical transformer of movements in which a distinctive peculiarity is an application of loss changes in radiation spreading in sensitive elements as ring loops deformed elliptically of multi-mode fiber light-guides forming a bundle that allows using a diode as a radiation source installed without a special alignment device. It is defined that a peculiarity of bending fiber-optical transformers of movement of a successive-parallel type is that in separate areas of rings a radius of curvature increases at the expense of deformation and the losses of radiation in these areas decrease, and in other ones this radius decreases that results in the increase of losses of the radiation spreading by light-guides. Overall losses directed at radiation in light-guides increase lineally with the increase of movement. There is carried out a choice of the optimum number of rings of a sensitive element and a choice of “source-radiation receiver” for obtaining a linear calibration characteristic of the sensor. It is shown that varying the number of coils in the bending fiber-optical transformer it is possible to change a range of movements measured ind a form of calibration characteristic of a transformer.

CCD Camera Calibration Technology Based on the Translation of Coordinate Measuring Machine

A new CCD camera calibration method based on the translation of Coordinate Measuring Machine (CMM) is proposed. The CMM brings the CCD camera to produce the relative translation with respect to the center of the white ceramic standard sphere along the X, Y, Z axis, and the coordinates of the different positions of the calibration characteristic point in the probe coordinate system can be generated. Meanwhile, the camera captures the image of the white ceramic standard sphere at every position, and the coordinates of the calibration characteristic point in the computer frame coordinate system can be registered. The calibration mathematic model was established, and the calibration steps were given and the calibration system was set up. The comparing calibration result shows that precision of this method is equivalent to that of the special calibration method, and the difference between the calibrating data of these two methods is within ±1μm.

Determination of Calibration Characteristics of X-Ray Fluorescent Analysis of Rhenium

Extraction concentration of rhenium by a melt of tetraoctylammonium bromide in paraffin was used with the aim of preparation of calibration samples for roentgen fluorescent analysis. The calibration characteristics of the roentgen fluorescent analysis of rhenium is established, its linearity is evaluated, a limit of detection and a limit of quantification (determination) of rhenium are calculated. The maximal<br />value of the relative total standard uncertainty of the calibration characteristic does not exceed 1.45 %.