36. Translate these phrases into English.

Измерять уровень влажности, оптимальный уровень, водяной туман, ультразвуковой, переносной, напольная модель, зона охвата, гигрометр, уровень шума, шипение.

GRAMMAR FOCUS

37. Translate the following sentences paying attention to the word worth.

1) There are also models that humidify and purify (or wash) the air - these are usually a more expensive, but may be worth considering. 2) Unless you want to monitor the room's moisture level and adjust settings to maintain it, these measurement features are very handy and worth the extra cost. 3) While it takes some time, it's worth it. 4) The industry accepted definition is that they are privately offered investment vehicles in which the contributions of the high net worth participants are. 5) What Chinese sentences are worth memorizing? 6) It is worth studying for this exam.

LANGUAGE DEVELOPMENT

38. Read the following text and fill in the words from the list below, answer the following questions and title the text.

a) readings	e) calculated	i) resistance
b) fan	f) measures	j) sophisticated
c) include	g) displays	k) hair
d) accurate	h) methods	l) dehumidifiers

There are various 1)_______ of humidity measurement, most of them using a device called a hygrometer. The hygrometer can work in a variety of ways, depending on the type, and is the most 2)_______ method for determining the humidity in the air. Some are connected to other devices called humistats, which are connected to humidifiers and 3)_______, and help control the level of humidity in the air.

One type of hygrometer uses 4)_______, usually human, that is attached to levers inside the unit. When the humidity in the air increases, the hair stretches, and then contracts when it decreases. The levers are generally connected to a dial which 5)_______ the humidity reading.

Other methods of humidity measurement using a hygrometer 6)_______ the psychrometer as well as electric hygrometers. Both methods are fairly accurate, although the electric version is more 7)_______ in design. There are also chemical hygrometers that are similar in effectiveness.

The psychrometer, also known as the two-bulb hygrometer, works by using two thermometer bulbs. One bulb is dry and 8)_______ the temperature in the air. The other bulb is covered in a substance, usually wick or muslin, and then wetted down. After being wetted, the bulb is exposed to moving air, either through a 9)_______ or by slinging the psychrometer through the air. As the water evaporates in the moving air, the temperature on the thermometer will drop. The amount the temperature drops helps to tell the amount of humidity in the air.

This method of humidity measurement is similar to when one goes swimming on a warm breezy day. Before entering the water, the temperature feels warm even with a breeze. If one jumps into the water and becomes wet and then gets back out, the breeze suddenly feels very cool. This is called evaporative cooling. Generally, the lower the humidity in the air, the bigger the drop in temperature.

Electric hygrometers work by measuring the electrical 10)_______ of a particular substance. Most substances, such as lithium chloride, have varying resistances to an electrical current based on the humidity in the air. These differences are then 11)_______ to display the humidity.

Chemical hygrometers work by using a chemical substance and exposing it to air. The chemical will be measured before being exposed and then again after. Any changes in weight indicate how much humidity is in the air.

Although hygrometers are fairly accurate methods of humidity measurement, the most accurate way of testing humidity on a global scale is through the use of satellites. Specialized satellites can detect the exact humidity in the troposphere, thereby giving accurate 12)_______ about weather conditions around the world. They are capable of tracking sudden changes in humidity and weather patterns to predict thunder storms, wind, and climate changes.

• What are the methods of humidity measurement?

• What device is the most accurate method for determining the humidity in the air?

• What is the function of a humistat?

• One type of hygrometer uses hair. How does it work?

• How does the psychrometer work?

• How do electric hygrometers work?

• How do chemical hygrometers work?

• What is the most accurate way of testing humidity on a global scale?

• What are satellites capable of?