technical science
Candidate of Physical and Mathematical Sciences Mukhtarova M.N., Doctor of Physical and Mathematical Sciences, Professor Yar-Mukhamedova G., Senior Lecturer Ermaganbetova S. D. undergraduate Mukanov M., student Khozhabayeva ZH.S.
Almaty, Kazakhstan
Automated measuring systems
Currently measuring systems (IS) are characterized by
the extensive use of information technology, personal computers (PCs) and other
computer equipment. Over the past decade, significantly changed the measurement
methods have been used more sophisticated and diverse methods of processing
measurement data. There is developing the fifth generation of IP - intellectual
and virtual systems based on PC-based and modern mathematical and software.
Kazakhstan applied hardware and software for the most
part imported. Along with them comes a large volume of English-language
documents and technical literature, the terms of which are moving in the
domestic literature, sometimes partially losing the original meaning.
Furthermore, many of the terms used, despite the wide use, remain fixed in our
standard documentation. For example, the term "data collection and
processing system" is derived from the phrase «data acquisition system»,
it is widely used in the domestic literature as a synonym for "measuring
system", but none of the domestic standards are not met.
Modern measuring systems are automated systems. In a
broad sense, automation – is the set of technical, organizational and economic
activities, giving the opportunity to lead the processes (production,
processing, information, etc.) without the direct participation of the person.
In a narrow sense as automation - is the use of technical means of automation
for measurement, control and management. Automated measuring systems (AIS) as a
subsystem may include more complex technical systems - Automated Control
Systems (ACS), an automated system for Scientific Research (ARS), and others.
Definition Metrology: "Measurement of physical
quantities - a set on the use of technical means of operation, storing unit of
a physical quantity, to ensure finding the ratio (in either explicitly or
implicitly) the measured value with its unit, and get the value of this
magnitude."
"Measuring instrument (SI) - is a technical means
for measurement having normalized metrological characteristics, reproducing and
(or) the storing unit of the physical quantity (EF), the size of which take the
same (within the established error) for a certain period of time."
Measuring system (IS) is defined as "a set of
functionally integrated measures gauges, transducers, computer and other
equipment placed at various points of the controlled object, and the like, for
the purpose of measurements of one or more physical quantities, characteristic
of the object, and generating measurement signals for different purposes".
Depending on the destination IP is divided into measurement information (MIS),
measuring control (IR) measurement control (I & C), measuring diagnosing (IDS),
and others. Here, we emphasize that the main goal of these systems is the
"measurement" and "development of the measurement signals."
EC distinguish two types:
- System issued by the manufacturer as finished
products equipped with the operational documentation containing normalized
metrological characteristics of measuring channels;
- System engineered for specific object of the
components of different IP various manufacturers with the acceptance of the
whole system as a finished product directly to the operation of the facility,
and the valuation of its metrological characteristics shall be in accordance
with the project documentation for the system and operational documentation on
its components.
-Second Version of the measuring system is used much
more often. Russian GOST 8.596-2002 gives a more detailed definition of the EC:
"IP - a set of measurement, binders computing
components constituting the measuring channels (IR), and auxiliary devices
(measuring systems components) functioning as a unit designed to: obtain
information about the object by means of measuring changes in the general case,
a plurality of variable distributed in time and space variables characterizing
this state; machine processing of measurement results; registration and display
of measurement results and the results of their machining; convert the data
into the output signals of the system for different purposes.
Thus, IP allocated, first, measuring and measuring
(binders computing) components included in the IC, and, secondly, two different
groups of components: the first consists in the IR, and the second auxiliary
(for example, blocks first "one". The measuring channel IC is defined
as "structurally or functionally allocated part of the IC performs the
function of a complete perception of the measured value to obtain the result of
its measurements, expressed by a number or a corresponding code, or to obtain
an analog signal, which is one of the options - a function of the measured
value." IR channels can be simple or complex. In a simple IR implemented a
direct measurement method by measuring successive transformations. Complex IC
in the primary section is a collection of a few simple IR signals from the
output of which is used to obtain a result of indirect, cumulative or joint
measurements. Thus, complex IC performs
collective processing output signals from the IR simple. Complex IR thus used
to obtain the results not direct, and indirect, cumulative and collaborative
dimensions.
The output of the IR should be measuring information.
A variety of measurement information is a signal and the countdown:
"Measuring signal – signal containing quantitative information about the
measured PV and the count indication of a measuring instrument - fixing values
of the number or by showing the SI unit at a given time."
Based on a study of the standard it can be concluded
that almost all the technical means of IP, regardless of their destination, are
part of simple or complex IR and SR are recognized. In other words, the EC does
not contain anything other than simple or complex IC and supporting components.
Channels of communication, modems, coders and decoders, switches, storage
devices, databases, computers - all that is considered an integral part of IR.
The standard specifies that the EC as a whole are a variety of SI and are
subject to all the general requirements for the SI.
IR includes SI such as transducers (SP). Transmitter
(SP) - a technical device with the regulatory metrological characteristics,
which serves to convert the measured value to another value or measuring
signal, convenient for handling, storage, display or transmission. Measuring
the information at the output SP, as a rule, is not available for direct
perception of the observer.
The converted value is transferred to the SP, called
the input and convert the result - the output value. The relation between them
is given by the conversion function, which is main metrological
characteristics.
For direct playback of the measured value are
transducers (PIP), which directly affects measured value and where there is a
transformation of the measured value for further conversion or display. One
type of primary device is a sensor - "structurally isolated primary
converter, which receives the measurement signals (he" gives "information)."
The sensor can be put to a considerable distance from the SI receiving its
signals.
By the nature of IP transformation can be analog,
analog-to-digital (ADC), digital-to-analog (DAC), that is, converts the digital
signal into an analog or vice versa. When the analog signal representation of
the form may take a continuous set of values, that is, it is a continuous
function of the measured value. In the digital (discrete) form it is presented
in the form of digital or groups of numbers.
Metrological IP software includes the following
activities: the valuation and calculation of metrological characteristics (MX)
IC, IC test for type approval EC and tested according to the approved type, IC
certification, verification and calibration of the IP. Rationing MX all IC
components is conducting other types of metrological activities: testing,
verification, calibration, type approval (or certification) certification.
Speaking of the metrological support of IP, we must
not forget that the current EC is composed of two major components: hardware
and software (SW). It is difficult to identify which of these parts is more
important, and both of them are directly dependent on the metrological
characteristics of the system. In some cases the effect of PO on the
measurement results is much higher than the hardware. Therefore, the software
must also be subject to metrological certification.
Literature:
1. Tsapenko MP Measuring information systems: structure and algorithms, schematic design: Textbook. manual for schools. - M .: Energoatomisdat 1985.2. JK Evdokimov, Lindvall VR, GI Shcherbakov LabVIEW for radio engineer from the virtual model to the real device. How to work in LabVIEW programming environment. - M .: DMK Press, 2007.
3. Lebedev AV, Petrov AB Computer-aided design
of measuring information systems / Methodical instructions for use when
designing diploma / MIREA. - M., 2004.