There is a number of the laboratory and test units demanding use of water of a certain rigidity. Besides, information on this parameter is necessary also at home - too hard water harmful influences ware and the equipment. It is possible to determine hardness of water in several ways.
Instruction
1. Hardness of water - one of its main ecological characteristics. Water is considered hard in case it contains a significant amount of cations of compounds of magnesium and calcium. It is known that when boiling water the so-called scum is sometimes formed. It arises only when the water which is exposed to heating is hard. When such water heats up to temperature of boiling, salts of metals drop out in a deposit and are laid on vessel walls. Hardness of water are usually expressed in millimolyakh on liter (mmol/l). It is not carbonate and carbonate. Carbonate water contains a significant amount of hydrocarbonate anions. Always calculate the general rigidity by summation of carbonate and not carbonate zhestkost.
2. If necessary on numerical value of rigidity carry water to one of the following three groups: - soft water - 3 ekv/l; - water of average rigidity - 3.0 up to 6.0 ekv/l; - hard water - 6.0 ekv/l. Hit of hard water in household appliances leads to emergence of malfunctions in it. So, for example, if the scum is besieged on any details washing or the dishwasher, then shortly it not only will fail, but also with high probability will become not maintainable. Never neglect measurement of hardness of water before application it in such purposes.
3. Hardness of water can be determined as empirically, and with use of measuring devices. Some dyud are able to define this indicator on taste, but this way it is undesirable to act. Try other method: add powder or soap to water. Being rigid, water it will be bad foams owing to existence of ions of magnesium and calcium. However, any of these methods does not allow to measure hardness of water in number. And by water preparation, for example, for an aquarium it is required to know for sure this indicator very. Apply so-called TDS meters to implementation of exact measurement of rigidity - the devices measuring concentration in water of salts and minerals. Also conductometers - devices for measurement of electric conductance of solutions became widespread. They allow not only to measure rigidity, to reveal the chemical and physical composition of the studied water, to check it for availability of impurity of any sort.
4. The most modern devices for determination of physical and chemical properties of water are multipurpose analyzers. They are capable to select automatically test of the analyzed water and to resist to influence of the particles weighed in it what devices of the previous generations are not capable of. Analyzers measure hardness of water not only in range of 0.05 - 5 ekv as other devices, but also at higher concentrations.