You will need
  • basic knowledge of mathematics
The term ppm means one-thousandth part of a substance present in another substance.

For example, the salinity of the water equal to 30.0 0/00 (ppm) means that in one liter of this water contains 30 grams of various salts.
The average salinity of sea water is 35 0/00.

In sea water dissolved 88.7% of the chlorides. Basically it is sodium chloride, i.e. table salt or NaCl.
The main method of determining the salinity of seawater – a method of titrovaniya.

To determine the salinity of the water in your aquarium with the marine animals, take away from it in a separate vessel, for example, 1 liter.

Add sample water a certain amount of silver nitrate (AgNO3). Silver nitrate will combine with sodium and chloride will precipitate.

Weigh the precipitated silver chloride and, given that the ratio of the amount of sodium chloride and other substances is always constant, calculate the salinity of the water.

However, it will be easier, if you did the measurement of salinity with a hydrometer, calibrated at room temperature.
With regard to the degree of intoxication, it is also expressed in ppm.

For example, if the device shows degree of intoxication 0.5 0/00, this means that in 1 liter of human blood dissolved 0.5 g of ethyl alcohol.

The amount of alcohol consumed with this indicator, different people will be different. Depend the result will be, first, floor, second, from the masses of people.

Women have the same dose of alcohol, and men are provided equal in weight will show on the device a greater degree of intoxication.

The reason is that in the male body proportion of liquid, including blood, is 70% of the entire mass, and in women only 60%.
To calculate an approximate degree of intoxication in‰, perform simple calculations:

The amount of alcohol consumed in grams multiply by the strength of the drink and divide the result by your weight with a coefficient of 0.7 or 0.6.

For example: 250 grams of vodka and multiply by 0.4 (the strength of vodka 40%) to obtain 100 g
Divide the result by your weight ( you are a man weighing 80 kg) and K = 0.7.
100 : (80х0.7) = 100 : 56 = 1.79 0/00 .

Such a result would be directly after the intake of 250 grams of vodka.