term "measure" refers to the evaluation of something.As part of Metrology this word has two different meanings.In the first case it is meant to indicate the establishment of some units.In the second measure is necessary to reproduce a single parameter value.
General
indication of a physical quantity called the necessary means to carry out measurements.It is used to reproduce and store predetermined physical unit.This could include, for example, measuring the weight or resistance.Throughout the world, there is a single definition for the concept of "metrology".This branch of science that studies the measurement methodology of their association, as well as rules for obtaining the required level of accuracy.The term "metrology" is derived from the Greek words that together mean "the study of measures."
Traceability
There are certain rules entries for which figures are recorded in terms of the adoption of laws.In addition, for the results of errors there are limits.Within this framework, indicators are considered acceptable.So are various types of measurement errors, which differ in degree.The main task of recording rules is to convert all the results obtained at different points at different moments, using various instruments and techniques in a single system.In our time, the need for more accurate and reliable data in the fields of science and economy.Therefore, it is intensively studied types of measurements.Metrology is of paramount importance.
measurement.Types of measurement
There are various interactive operation whose task is to set the type of relationship between the amount of that estimate, and one that very few.The latter is fixed in the measuring device.The numeric value - is the data.They have another name - an indicator of a physical quantity.There are different types of measuring instruments.They are themselves units and devices, and specific transmitters and system and installation.Extensive and meaning of the term "measure".Types of measurement is also very diverse.However, there are some common points.Types and methods of measurement of one united structure.Assessment procedures consist of two stages.First of all you need to compare the measured value with a reference unit, and then convert to the desired format, addressed to a particular method.
Variability
diversity is not only the types of measurements.Classification of devices for this procedure also assumes the existence of different sections.Adopted systematization by appointment, for example.One group of instruments called exemplary, and the other - the workers.The first required in order to use them as a benchmark to check the accuracy of other measurements.By working are those that are designed to estimate the size of the specific values used by man.We can say that the meaning of such a classification is not the accuracy of the instrument and the differences of purpose.There are various means by which the measurement is made.Types include measurements and special measures by which reproduce the magnitude of any particular size.
Single-valued and multi-valued measures.Differences also exist
unambiguous and multi-valued measures.The former include those that are capable of displaying only the values with the same size.Available with multi-playback sequence of different sizes.Such a measure could be called, say, millimeter ruler.There are also a kind of kit, which are formed of different sets of steps.They recreate the intermediate and summary values of.Moreover, action by interacting, can perform an overall job and can act separately each.In order to compare the value of the measure, it is necessary to use a special device - a comparator.In the role of this tool often act-equal scales and measuring bridge.If more unambiguous measures to study, it is possible to say that to them also rank the samples and substances acting in this role.They have a predetermined composition and properties.Slight deviations are unacceptable.These reference materials can help to assess the roughness, hardness, identify any other material properties.Samples help to create points, which form the scale.Zinc and gold, for example, is used when it is required to reconstruct a certain temperature.
discharges
error in the assessment of all measures classified by several successive discharges.In the case of deviation from the standard measures themselves, the class division.The units are checked errors specific discharge measurement devices, allowing them to rank the samples.
converters.General
appliances for measuring, which is formed from information obtained after the measurement data such that the ability to convert, store and handle, but does not reveal them visual access, called a transducer.What is its effect?Let us examine this in more detail.
essence of conversion
When the value is only prepared for the processing, it is called the input value.And the information becomes known as "output."The converter-amplifier - is a device that does not change the physical state of the data being processed, and the transformation is a linear function.The term "enhancer" is used in conjunction with a word that explains its action.For example, "a voltage amplifier."If during the conversion value is converted to another, the name of the device gets a new value - "Electromechanical".Types of transducers
Depending on what part of the device it is, the transducer may be a primary.This means that the measured value passes through it immediately.It can be transmitted.The values occur following treatment.The converter may be an intermediate.It is located behind the primary.
devices.General
Measuring instruments considered such means to obtain data on the magnitude, that represent them in a format that is accessible for visual inspection.Depending on the type of assessment, they are combined in certain groups.So, it is considered the most common devices, providing direct measurements.Their peculiarity is that they convert the raw data, leaving information about their initial state.There are tools allows you to perform and indirect measurement.
Instruments comparison
However, devices with direct action are not the most accurate.Much higher this characteristic from the device comparison.His work is based on a comparison of the data obtained in the measurement of the value of the study with the already known information about other values.This method has a name, and "indirect measurements."Their preparation is possible if the source data.In other words, the parameters of the generated indicators that provides a direct measurement.Types of measurement are several categories.In order to compare values, you must use compensation or bridge circuits.The first compared the quantities that have some power or force.This method relies on the fact that the value being compared is connected to the contour chain, and exploring their manifestation.In the same case, if the value is considered to be passive, ie, it has a resistance bridge circuit is used.
distribution by the method of counting
have devices have different methods for reference data for the studied variables.Therefore, a special classification.On this basis one can conclude that there reproducing devices, which include not only analog and digital.Another type of devices - those that record information.The most popular are analog devices.Their component is responsible for maintaining the reference is formed of two parts.The first is the scale of which is connected to the moving part.Another element of the device - a pointer connected to the housing of the device.Action meters, whose work is based on the principle of digital, is the result of mechanical and electronic elements.
Variability of recording method
There is another classification of registering devices.For example, the method by which write data recording devices.There are instruments, recorders and printers.The first offer received and processed information and aggregate measure in the form of graphs, charts and diagrams.Registrars working on the second principle, give results on the paper, converting them into numerical series.Very frequent devices operating on model comparison, which are a combination of all the above types, that is, they represent a set of reference works on a scale and a digital method.Data logging, processing, and printing can be done in the form of graphs with charts and rows of numbers and numerical values.
Extras assessment
There are also auxiliary devices and tools for measurement.A feature of these devices is that they not only conduct research on their own values.They can regulate the operation of the main element, its effect in changing the moment of reading information, and when it is processed or SERP.Data which provides additional tools to help monitor and edit the testimony devices.For example, for a more efficient work of the thermometers must also install gauges that measure the ambient pressure.In addition, the auxiliary equipment can change the setting operation of the meter.Thus, in the case of using the device for recording the level of moisture is necessary to set a range of values.
Settings
There are times when, in order to get a more accurate measurement of the device is not enough.In this case, we are going to complete systems consisting of devices for different purposes.They are arranged in sequence in a limited area.Some of the devices used are converted cumulative measurement in a single system.It is given responsible for the collection, organization and processing of information to the observer.
Systems
On another level, there are measuring systems.Unlike such complexes by the above described settings is that they may be scattered over a vast territory, and to communicate information through special channels.The data in these systems are available in two types.One of them is accessible to a real person, student performance.It is engaged in the processing of other computer.
Indicators
There are instruments whose task is to read the manifestations of physical properties.They are called indicators.Another of the school chemistry course all known litmus test related to the means of indication.The compass needle is also considered such a device.Moreover, a counter that displays the level of fuel in automotive fuel tank, is also an indicator.
