Infrared gas analyzer

УТВЕРЖДАЮ

Проректор по учебной работе

профессор

_________________________

М.А. Иванов

«____» ____________ 2012 г.

ТЕСТ К ЭКЗАМЕНУ

По учебной дисциплине

«Иностранный (английский) язык»

IV семестр

очно-заочный факультет

Для студентов специальности:

200101.65.02 Контрольно-измерительные приборы и системы

Вариант 3

Составители: доц. Р.Д.Кирпичников, каф.ИЯ

ст. преп. С.П. Егоров, каф.ИЯ

Санкт-Петербург

I. БЛОК ЧТЕНИЯ.

Read the text 1.

Choose the best alternatives 1, 2, 3, 4 or 5 to answer the questions.

Infrared gas analyzer

An infrared gas analyzer measures trace gases by determining the absorption of an emitted infrared light source through a certain air sample.

Trace gases found in the Earth's atmosphere get excited under specific wavelengths found in the infrared range. This technology can be understood when considering the greenhouse effect.

When sunlight hits the Earth's surface, the incoming short wave radiation gets turned into long wave infrared radiation that is reflected back into space. If the planet has a thick atmosphere, much of this radiation is absorbed by the "greenhouse gases" in the atmosphere which act as an insulative blanket. The infrared gas analyzer works using a similar principle.

Infrared gas analyzers usually have two chambers, one is a reference chamber while the other chamber is a measurement chamber. Infrared light is emitted from some type of source on one end of the chamber, passes through a series of chambers that contains given quantities of the various gases to be analyzed.

For instance, if the analyzer is to measure carbon monoxide and dioxide, the chambers must contain a certain amount of these gases. The infrared light is emitted and passes through the sample gas, a reference gas with a known mixture of the gases to be measured and then through the "detector" chambers containing the pure forms of the gases to be analyzed.

When a "detector" chamber absorbs some of the infrared radiation, it heats up and expands. This causes a rise in pressure within the sealed vessel that can be detected with a pressure transducer. The combination of output voltages from the detector chambers from the sample gas can then be compared to the output voltages from the reference chamber.

№	Вопросы	Варианты ответов
1.	What does an infrared gas analyzer do?	1. Cleaning. 2. Calculation 3. Measurement. 4. Repairs. 5. Navigation.
2.	What is reflected back unto space?	1. Long wave infrared radiation. 2. Sunlight. 3. Short wave radiation. 4. The Earth's atmosphere. 5. No information provided.
3.	What gets excited in the Earth's atmosphere?	1. Specific wavelengths. 2. Ultraviolet rays. 3. Radio waves.. 4. The air. 5. Trace gases.
4.	What do the "greenhouse gases" do?	1. They absorb light. 2. They radiate infrared rays. 3. They absorb the planet’s atmosphere. 4. They absorb much of the reflected infrared radiation. 5. No information provided.
5.	What does an infrared gas analyzer have to do with the greenhouse effect?	1. It functions using other technologies. 2. It operates similarly. 3. It helps overcome this effect. 4. This effect complicates using the analyzer. 5. No information provided.
6.	What do chambers have to do with an infrared gas analyzer?	1. They are the parts of this instrument. 2. The analyzer is kept inside one of them. 3. They have to be used parallel with the analyzer. 4. They are used to test this instrument. 5. No information provided.
7.	What does infrared light do in an infrared gas analyzer?	1. It is to be measured by this device. 2. It allows to see objects in the darkness. 3. It produces gases by passing through the chambers. 4. It is produced by passing gases. 5. It is emitted inside the analyzer for passing through gases.
8.	What does heat up and expand in an infrared gas analyzer?	1. The infrared radiation 2. Absorption. 3. A detector chamber. 4. A reference chamber. 5. No information provided.
9.	How does the pressure act within the sealed vessel?	1. It remains the same. 2. It increases. 3. It changes. 4. It decreases. 5. No information provided.
10.	What does an infrared gas analyzer compare analyzing gases?	1. The chambers. 2. The detectors. 3. The sample gases. 4. Output voltages. 5. No information provided.