Metod_англ.мова_

4.Does the result of measurement differ from the true value of the physical quantity being measured?

5.Why can true value never be determined exactly?

V Analyze the structure of the following words and give their initial forms: qualitative, irrespective, suitable, meaningful, combination, experimentation, experimenters, comparable, absolutely, proceeding, unlimited.

VI Give a summary of the text and be ready to speak on the topic.

STANDARDS ORGANIZATION

A standards organization, also sometimes referred to as a standards body, a standards development organization or SDO (depending on what is being referenced), is any entity whose primary activities are developing, coordinating, revising, amending, reissuing, interpreting, or otherwise maintaining standards that address the interests of a wide base of users outside the standards development organization.

Most standards organizations are established exclusively for the purposes outlined above. There are, however, a few notable examples of organizations who unintentionally acquired a status as the standards setter when a standard they originally developed for internal use has become widely used and recognized by the industry as the de facto industry standard.

Normally, the term standards organization does not include the parties participating in the standards development organization in the capacity of founders, benefactors, stakeholders, members or contributors, who themselves may function as the standards organizations. Generally, any given standards organization can be classified by its role, position and the extent of its influence on the local, national, regional and global standardization arena. By geographic designation, there are international, regional, and national, standards bodies (the latter often referred to as NSBs). By technology or industry designation, there are standards developing organizations (SDOs) and also standards setting organizations (SSOs) also known as consortia. Standards organizations may be governmental, quasi-governmental or nongovernmental entities. Quasiand non-governmental standards organizations are often non-profit organizations.

There are many international standards organizations, but the three international organizations having the highest international recognition are the International Organization for Standardization (ISO), the International Electrotechnical Commission (IEC), and the International Telecommunication Union (ITU). All three of these have existed for more than 50 years (founded in 1947, 1906, and 1865, respectively) and they are all based in Geneva, Switzerland. They have established tens of thousands of standards covering almost every conceivable topic.

5

: )

Grammar: Tense forms in Active and Passive. (Review).

I Read the text and translate it in a written form.

What is metrology?

Physical quantities are measured with the aid of measurement devices. In view of physical quantities and the variability in the requirements and conditions of measurements, measurement technology offers a wide range of measurement devices. Functionally, they may be classed into standards, instrument transducers, instruments, measurement set-ups, and measurement systems.

The performance of measurement devices may be stated in more than one way, but the most important description is in terms of metrological characteristics, that is characteristics essential in assessing the accuracy of measurements. As a rule, these characteristics are subject to mandatory specifications – a feature which makes it possible to assess the accuracy of measurements in a meaningful manner.

One such characteristic of general nature is the accuracy classes. It is determined by the limit of error and by some other properties of measurement devices that may affect the accuracy of measurements.

Apart from measurements, information about objects in the material world can be acquired by counting, monitoring, diagnostics, and pattern recognition.

Counting refers to determining the number of identical objects in a given set or collection.

Monitoring has to do with establishing whether the condition of the object being monitored corresponds to the required one. In monitored, there is no need to know the numerical value of the monitored quantity. However, monitoring includes a number of operations inherent in measurements (conversion and comparison).Therefore, the accuracy aspects are as important in monitoring as they are in measurements. Monitoring can be effected by a human operator assisted by process instrumentation, or automatically by automatic facilities.

In many cases a failing object can be restored to normal only after one has identified the elements that have caused the trouble. This is done by what is known as diagnostics – a procedure by which one detects and isolates faults in the elements of the object on hand, that is, determines its serviceability. This is done with the aid of diagnostic systems.

The manufacture and use of measurement device and all scientific matters related to both belong to the realm of measurement technology. Scientific foundations for measurement technology are provided by metrology – a science which has to do with measurements, the trace-ability and uniformity of the methods and means used for the purpose, and the ways and means of achieving the desired accuracy.

II Answer the following questions:

1.What is needed measurement for?

2.What are measured with the aid of measurement devices?

3.What are metrological characteristics?

4.How can information about objects in the material world be acquired?

5.What is metrology?

9. The development of units of measurement… investigated in considerable detail. a) has been b) is c) are being

10.With low level signals one … rather sophisticated comporator designs. a) have to use b) has to use c) used

V Analyze the structure of the following words and give their initial forms:

Physical, functionally, numerical, restored, variability, instrumentation, automatically, serviceability, scientific, quantity, technical.

VI Give a summary of the text and be ready to speak on the topic.

HISTORY OF MEASUREMENT

Units of measurement were among the earliest tools invented by humans. Primitive societies needed rudimentary measures for many tasks: constructing dwellings of an appropriate size and shape, fashioning clothing, or bartering food or raw materials. The earliest known uniform systems of weights and measures seem to have all been

created sometime in the 4th and 3rd millennia BC among the ancient peoples of Mesopotamia, Egypt and the Indus Valley, and perhaps also Elam (in Iran) as well The most astounding of these ancient systems was perhaps that of the Indus Valley Civilization. The Indus Valley peoples achieved great accuracy in measuring length, mass, and time. Their measurements were extremely precise since their smallest division, which is marked on an ivory scale found in Lothal, approximately 1.704mm (the smallest division ever recorded on a scale of the Bronze Age). The decimal system was used. Other systems were based on the use of parts of the body and the natural surroundings as measuring instruments. Early Babylonian and Egyptian records and the Bible indicate that length was first measured with the forearm, hand, or finger and that time was measured by the periods of the sun, moon, and other heavenly bodies. When it was necessary to compare the capacities of containers such as gourds or clay, or metal vessels, they were filled with plant seeds which were then counted to measure the volumes. When means for weighing were invented, seeds and stones served as standards. For instance, the carat, still used as a unit for gems, was derived from the carob seed.

Our present knowledge of early weights and measures comes from many sources. Archaeologists have recovered some rather early standards and preserved them in museums. The comparison of the dimensions of buildings with the descriptions of contemporary writers is another source of information. An interesting example of this is the comparison of the dimensions of the Greek Parthenon with the description given by Plutarch from, which a fairly accurate idea of the size of the Attic foot is obtained. In. some cases, we have only plausible theories and we must sometimes select the interpretation to be given to the evidence.

By studying the evidence given by all available sources, and by correlating the relevant facts, we obtain some idea of the origin and development of the units. We find that they have changed more or less gradually with the passing of time in a complex manner because of a great variety of modifying influences.

6

) I

Grammar: Modals with Passive (Review)

I Read the text and translate it in writing.

Units of Measure of Physical Quantities

By physical quantities are meant properties of substances that may differ quantitatively for various bodies or different for one and the game substance. Such quantities

include length, mass, volume, temperature, pressure and other properties. Each quantity may have different concrete values, that are - estimated, quantitatively by measuring-.

The process of measuring consists in comparing a given quantity with some definite value of it, assumed as unity. The result of measuring, expressed in a denominate (concrete) number, shows how many times the given quantity is greater than the unit of measurement, or what fraction of it constitutes. The magnitude of a unit of measurement can be set arbitrarily, but provided it can be precisely reproduced by material specimens or by standard methods.

Most of the known quantities are interrelated by quantitative relationships, therefore the quantitative magnitudes of units are chosen arbitrarily only for some independent units, that are referred to as basic units. All other units, whose magnitude or value is determined based on mathematical relationships through the basic units, are known as derived units. The whole set of basic and derived units comprises the system of measuring units for physical quantities.

All through the development history of the measuring technique the values of the measuring units for various t quantities have been changed repeatedly, with the values being chosen at random in an unorganized way. As a result, until now, practical use is being made of various systems of units, and also of individual non-systematized units, and this creates considerable inconvenience in science, engineering, in production and other realms-of public work and activity.

Until I960 the value of the basic unit of length was determined by means of a material standard - the international meter prototype. The new natural meter standard adapted at the XI General Weights and Measures Conference can be reproduced with the greatest accuracy through the wavelength of luminous radiation.

When an electric field effects the atoms of some chemical, elements, electrons displace from one orbit or level to another. Such displacements, associated with the change in the internal atomic energy, are referred to as transitions. Transitions of electrons are accompanied by luminous radiation which is characterized by a definite wavelength, constant in time.

Kilogram - unit of mass, equal to the mass of the international prototype kilogram.

The material standard of mass has been fabricated when the metric system of measures has been conceived. At the same time 43 copies of the prototype kilogram standard were made and handed over to different countries.

II Answer the following questions:

1.What properties do physical quantities include?

2.What does the result of measuring show?

3.Why does comprise the system of measuring units?

4.When did the new natural meter standard adopt?

5.When was the material standard of mass fabricated?

III Choose the Ukrainian equivalents from the right column:

IV Choose the right variant from the given in brackets:

V Analyze the structure of the following words and give their initial forms:

Difference, mathematical, definitions, reproducing, transitions, independent, impossible, international, characterized, corrections

VI Give a summary of the text and be ready to speak on the topic.

Non-contact temperature measurements

One of the non-contact methods for temperature measurements involves the use of pyrometers.

The temperature at the surface of hot bodies raised to anywhere from 30° to 2500° C Is usually measured by total radiation pyrometers which are accurate to within + -1% of the range. Their accuracy can be affected by the quality of the medium

between the instrument and the object under test-any smoke, mist, soot or other particulate substance present can absorb or scatter the energy emitted by the hot body of interest. Better accuracy is obtained with disappearing-filament and photoelectric pyrometers.

The non-electrical quantities that have to be measured and the instruments used for the purpose are too many and too diverse for any; one to attempt and give an exhaustive coverage of all or even a sizeable proportion of them. Therefore, we will limit ourselves to the measurement of a limited range of quantities most often encountered in science and technology. For example, the need to measure temperature, concentration of gases and liquids, and pressure of gases and liquids is a regular feature of the chemical process industry., the petroleum and petrochemical industry, metallurgy, thermal Power generation, food processing, agriculture, and medicine. Pressure, dimensions, and displacements need to be measured in instrument-making and mechanical engineering, especially in flexible manufacturing systems which employ industrial robots. In view of these needs, the section that follows deals with the measurements of temperature, pressure dimensions, displacements, and concentration of liquids and gases.

6

) II

Grammar: Modals with Passive (Review)

I Read the text and translate it in writing.

Classification of Measures and Measuring Instruments

The technical means that are used for taking measurements are known as measuring apparatus, including measures measuring instruments and devices.

A measure is defined as a device, substance or body , designed for offering a material representation of a unit of measure, and also of its multiple and submultiple values.

There are measures of constant and variable values. Constant value measures have one definite magnitude. Measures of this kind include weights, measuring (graduated) flasks, all kind of gauges, standard resistors, tuning forks.

In addition to its full value, a variable measure contains fractional values. A rule with divisions is a variable measure.

Individual similar measures of various values can be used to make up a set of measures. A combination of measures taken from one set makes it possible to have available measures of different value, but each measure of the set can be used

individually. Classified as of measures are: set of weights used with a beam balance; get of weights used in conjunction with a piston-type or dead-weight pressure gauge, a number of flasks used for measuring the volume of liquids.

A set of measures, making up a single device, is referred to as a box of measures. There are resistance boxes, inductanceand capacitance boxes. Such boxes make it possible to obtain measures of different values, though it is impossible to remove each individual measure from the box for independent usage.

Measures may be made both in the form of simple devices (rules, weights, flasks) and of rather complex means (cadmium standard cell, tuning fork generator, etc.).

It is possible to use as measures some substances that possess under certain conditions characteristic physical properties such as, for instance, constant melting temperature, boiling temperature or a definite calorific value.

Measures by themselves enable but an number of measurements to be accomplished. Most measurements are made with the aid of special measuring instruments.

Measuring instrument is the name given to a device designed for and enabling to compare some quantity with its unit of measure.

There exists a great variety of measuring instruments, differing both in the principle of operation and, design. Measuring instruments can be classified in accordance with many features: the method of obtaining the result of measurement; the method of taking readings; mode of application; class of accuracy, principle of operation; kind of quantity measured; method of installation, etc.

In respect to the method of obtaining the result of measurement, measuring instruments are classified as direct-reading, comparing and adding (integrating) instruments.

II Answer the following questions:

1.What is a measure?

2.What do constant value measures include?

3.What are sets of measures classified?

4.What is measuring instrument?

5.How can measuring instrument be classified?

III Choose the Ukrainian equivalents from the right column:

IV Choose the right variant from the given in brackets:

V Analyze the structure of the following words and give their initial forms:

Independent, consideration, replacement, frequently, electromechanical, specification, measurements, instrumentation, automatically, scientific.

VI Give a summary of the text and be ready to speak on the topic.

Temperature measurements

At present, temperatures have to be measured from very low (close to absolute zero) to very high (running into tens of thousands of kelvins). In practice, one is most often concerned with steady or slowly varying temperatures (at a rate of about one degree C pear minute). In some cases, however, measurements may involve temperatures varying at a rate of several hundred degrees per second, as is the case with the air-gas ducts of an aircraft engine. The maximum rate of pulsations in the temperature being measured is at present limited to tens of kilohertz. Accuracy requirements in temperature measurements sometimes come very nearly to the highest limit in metrology in general.

Temperature measurements may only be as accurate as is the standard used. A temperature standard is a set-up which reproduces the temperature scale between two reference point.