To measure humidity level in the apartment or the private house, the special equipment is necessary. Today to buy the device which will show the relative or absolute humidity of air does not make big problems, but how to make a right choice?
What humidity we measure
Humidity – not the temperature or time. At its measurement there are some nuances. Therefore before going to shop behind a desired priborchik, it is worth studying a subject a little. For a start it is necessary to understand the basic concepts. The humidity of air is absolute and relative. Absolute is density in air of water vapor. At various temperature this size will be unequal. And here relative air humidity is what constantly speak in a weather forecast and weather reports about. Speaking a simple language, this size shows what amount of moisture is not enough for air till the moment when its condensation begins. The device for determination of relative air humidity is also necessary for the children's room, office or other household use.
Hygrometers
The device measuring humidity of air is called a hygrometer. Today in shops most often it is possible to meet electronic hygrometers of various modifications. For the children's room and simple systematic control of humidity in the house, such priborchik can be quite enough especially as also the price at it acceptable. However do not differ in high precision of the indication of such hygrometer. They can sometimes give an error within 20%.
The mechanical hygrometer will be more expensive electronic, but and will begin to work more precisely. The device is a scale with an arrow. There are hair and film modifications of such device. In humidity of air, the first on changes, the long female hair connected to the metering device reacts. In a film hygrometer a role of a measuring element is played by a special thin film. However it is necessary to consider that both hygrometers will supply with quite exact information at low temperatures, and here during a heat of their indication can be distorted.
Psychrometer
The most precision instrument for determination of relative air humidity at various temperatures is the psychrometer. The difference between temperature on two scales of the thermometer – dry and damp is the basis for its work. However, for obtaining result, it is necessary to make some efforts: to moisten fabric with water, to place in the device and to wait some time, and then still to calculate the answer according to the special table. However if you look for really reliable data about humidity and fluctuations in 15-20% do not satisfy you, buy the psychrometer with two scales. It will not bring you.