THERMOCOUPLE

Allhot bodies emit radiant heat. А radiation pyrometer determines the temperature of the hot body by measuring the radiant heat. The radiation is usually measured with а thermocouple, though it is sometimes better to use а photoelectric cell. А thermopile is an assembly of thermocouples placed close together and connected in series. А thermocouple is simpler and usually cheaper than а radiant pyrometer. Most temperature measurements are therefore made with thermocouples. However certain measurements that are difficult or impossible to make with а thermocouple can be made by radiation methods. The following example shows the type of application for which radiation pyrometers are suitable.

Some measurements are made at temperatures which are too high for thermocouples, or conditions leading to rapid contamination of the element. For example, the roof of a steel melting furnace may reach а temperature of 1700'C in an atmosphere which will destroy any thermocouple in a day or two. Such а temperature is best measured with a radiation pyrometer.

1. Find in Text 8A the definition of the term "thermopile".

2.Rearrange the sentences to make а summary of the text

1. А thermocouple is cheaper than а radiant pyrometer. 2. All hot bodies emit radiant heat. 3. А very high temperature is measured with radiant pyrometer. 4. The radiation is usually measured with а thermocouple. 5. Some measurements are made at temperatures which are too high for thermocouples. 6. А radiation pyrometer determines the temperature of the hot body by measuring the radiant heat.

АТОМIС ENERGY

А man trying to see а single atom is like а man trying to see а single drop of water in the sea while he is flying high above it. He will see the sea made up of а great many drops of water but he certainly will not be ableto see а single drop. By the way, there are so many atoms in the drop of water that if one could count one atom а second, day and night, it would take one hundred milliard years. But that is certainly impossible.

Man has, however, learned the secret of the atom. He has learned to split atoms in order to get great quantities of energy. At present, coal is one of the most important fuel and our basic source of energy. It is quite possible that someday coal and other fuel may be replaced by atomic energy. Atomic energy replacing the present sources of energy, the latter will find various new applications.

The nuclear reactor is one of the most reliable "furnaces" producing atomic energy. Being used to produce energy, the reactor produces it in the form of heat. In other words, atoms splitting in the reactor, heat is developed. Gas, water, melted metals, and some other liquids circu1ating through the reactor carry that heat away. The heat may becarried to pipes of the steam generator containing water. The resulting steam drives а turbine, the turbine in its turn driving an electric generator. So we see that а nuclear power-station is like any other power-station but the familiar coal-burning furnace is replaced by а nuclear one, that is the reactor supplies energy to the turbines. By the way, а ton of uranium (nuclear fuel) can give us as much energy as 2.5 to 3 million tons of coal.

The first industrial nuclear power-station in the world was constructed in Obninsk not far from Moscow in 1954. It is of high capacity and has already been working for many years. One may mention here that the station in question was put into operation two years earlier than the British one and three and а half years earlier than the American nuclear power-stations.

А number of nuclear power-stations have been put into operation since 1954. The Beloyarskaya nuclear power-station named after academician Kurchatov may serve as an example of the peaceful use of atomic energy in the USSR.

Scientists and engineers achieved а nuclear superheating of steam directly in the reactor itself before steam is carried into the turbine. It is certainly an important contribution to nuclear engineering achieved for the first time in the world.

We might mention here another important achievement, that is, the first nuclear installation where thermal energy generated in the reactor is transformed directly into electrical energy.

Speaking of the peaceful use of atomic energy it is also necessary to mention our nuclear ice-breakers. "Lenin" is the world's first ice-breaker with а nuclear installation. Its machine installation is of а steam turbine type, the steam being produced by three reactors and six steam generators. This ice-breaker was followed by many others.

The importance of atomic energy will grow still more when fast neutron reactors are used on а large scale. These reactors can produce much more secondary nuclear fuel than the fuel they consume.

1. Translate the following sentences into Russian.

1.Working at his new device, the inventor made numerous experiments. 2. We have been speaking about the peaceful use of atomic energy. 3. In future the nuclear reactor must be one of the most reliable "furnaces" producing atomic energy. 4. Atomic energy being developed in а reactor in the form of heat, we can get both heat and electrical energy. 5. The construction of power-stations operating on atomic fuel and generating electric current is quite necessary. 6. Being а source of heat and electrical energy, atomic energy can also serve us in medicine. 7. The energy sources of the world decreasing, it is necessary to turn to atomic energy. 8. Water falling from its raised position changes potential energy into kinetic energy.

2. Fill in the blanks with prepositions,

1. Electricity plays an important' part ... everyday life. 2. It is difficult to imagine now how people could do... electricity. 3. As my friend lives near the institute he usually goes there ... foot. 4. 1 often go ... bed late ... night. 5. One form ... energy can be changed ... another form. 6. Only а little part... solar energy is used directly ... present. 7. Soviet scientists made а great contribution ... nuclear engineering.

3. Define the following words according to the model given below.

Model: The motor is а device transforming electric energy into mechanical energy.

energy, battery, kinetic energy, nuclear reactor, potential energy

<== попередня сторінка	\|	наступна сторінка ==>
	\|	ELECTRICITY

Не знайшли потрібну інформацію? Скористайтесь пошуком google:

Генерація сторінки за: 0.005 сек.