When using d-c, a label indicating the voltage level is to be fitted on switchboards feeding the discharge lamps.
>1 арматура, >2 колпак, >3 решетки, >4 допустимый
32 15
Ноте exercise. Check your reading skills,
a) Read the text.
Thermocouple meters (Fig. 2) convert applied current (a-c or d-c) by thermoelectric effects into deflection currents which register on a PM moving-coil couple actuated by heat generated at the junction formed by two strips of dissimilar metal. One strip carries the heat-generating input currents, the other carries heat-produced currents to the meter movement.
33
3 Заказ № 864
Thermocouple meters are used to measure a wide range of either a-c or d-c currents and give an accurate picture of the effective, or heat-j producting, value of a current noi matter what its nature. The meters are relatively expensive and the thermal delay in converting input electricity to heat makes them sluggish.
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Fig. 2. Arrangement of thermocouple meters |
b) Place a transparent film on the text and insert every fifth word (22) which is shaded on the film.
c) Fill in the blanks in such a way that it makes sense.
1. The convertion of applied current into deflection current is through a thermocouple.... a) actuated by two strips of dissimilar metal; b) actuated by heat generated at the junction; c) generated by input currents.
2. Thermocouple meters are used to... . a) measure voltage by the comparison method; b) operate through the electrostatic repulsion;
c) measure a wide range of either a-c or d-c currents.
3. Thermocouple meters are relatively. ... a) expensive; b) large;
c) cheap.
Now record your time and results 22—20 correctly inserted words+3 correct answers per 8 minutes get you an excellent mark.
20—18+2 per 9 ms — good. 18—17+2 per 10 ms — satisfactory.
Hometask: Ex, 31, 32.
Key
6 — aehn; 7 — cdgiklnprsuvxzb'c'; 8 — cdghjmp; 9—1, 4, 5; 11 — Iabiq, 1 lcegklmoprs; 12 — adfgj; 13—1. Этот механизм вышел из употребления в наши дни. 2. Почему вы не пользуетесь этим двигателем? 3. Эта конференция полезна всем нам. 4. Боюсь, что я здесь бесполезен. 5. Не стоит (не имеет смысла) пользоваться этим ваттметром. Кажется, он испортился. 17—2, 3; 22—Т. У него было мало времени, так же как и у других студентов. 2. В английском парламенте 2 палаты: палата общин и палата лордов. 3. У этих двигателей нет ничего общего. 4. Как вам нравится этот счетчик? — Знаете, в нём нет ничего особенного. 5. Ваша идея незаурядна, 29 — Frequency meter. 32 — 1Ь2сЗа.
SECTION 2 (3+1+3)