For determination of humidity of steam the modern experts often use the specialized devices based on mechanical office of water on overheating by means of electric current, etc. But how to define humidity of steam if devices of this sort are not had near at hand?
It is required to you
- - two thermometers (liquid mercury);
- - small piece of a gauze;
- - vessel;
- - table for definition of a dew point;
- - psikhrometrichesky table.
Instruction
1. A way you pervyyotberit small test of air in the prepared in advance tight vessel. Cool a vessel with contents. Cooling air in a vessel, it is necessary to control constantly all process not to miss that moment when on walls of a vessel dew drops appear.
2. Record temperature at which the first drops of dew are formed. This figure will also be a dew point at which steam which is available in a vessel will become saturated and will begin to turn into liquid gradually.
3. Determine density of saturated steam corresponding to the taken temperature by the table. The received figure will show absolute humidity of steam.
4. A way you vtoroyvozmit two prepared thermometers. Wind a bubble of one of them in which there is a mercury, several layers of a gauze. Lower the wound part in water and take out on air. Wait until temperature is recorded on thermometers. At the same time it is necessary to know that temperature on the damp thermometer will be lower, than on dry. Write down temperatures and find their difference.
5. Find according to the psikhrometrichesky table a column with value which was shown by the dry thermometer. It is possible to take the closest value in the table if there is no exact. Carry out on a line before crossing of columns in which there is a figure corresponding to the calculated difference of temperatures.
6. Look at figure. It will be specified as a percentage and will mean relative humidity (φ). Find according to the second table density of saturated steam (ρн) for temperature shown by the dry thermometer.
7. Find humidity of steam, having increased the found relative humidity (φ) by density of saturated steam (ρн) and having divided the received result into 100%, that is on a formula: ρ = φ *ρн / 100%