negative charge – The electrical charge on an electrode or ion in solution, due to the presence of and excess of electrons.
neutral – In electrical systems, the term used to indicate neither an excess nor a lack of electrons; a condition of balance between positive and negative charges. In chemistry, the term used to indicate a balance between acids and bases; the neutral point on the pH scale is 7.0 indicating the presence of equal numbers of free hydrogen (acidic) and hydroxide (basic) ions.
neutralization – In general, the addition of either an acid or a base to a solution as required to produce a neutral solution. The use of alkaline or basic materials to neutralize the acidity of some waters is a common practice in water conditioning.
noncarbonate hardness – Water hardness due to the presence of compounds such as calcium and magnesium chlorides sulfates or nitrates; the excess of fatal hardness over total alkalinity.
operating pressure – The range of pressure, usually expressed in pounds per square inch, over which a water conditioning device or water system is designed to function.
osmosis – A process of diffusion of a solvent such as water through a semi-permeable membrane which will transmit the solvent but impede most dissolved substances. The normal flow of solvent is from the dilute solution to the concentrated solution.
oxidation – A chemical process in which electrons are removed from an atom, ion or compound. The addition of oxygen is a specific form of oxidation. Combustion is an extremely rapid form of oxidation, while the rusting of iron is a slow form.
particle size – As used in industry standards, the size of a particle suspended in water as determined by its smallest dimension, usually expressed in microns.
parts per million (ppm) – A common basis for reporting the results of water and wastewater analysis, indicating the number of parts by weight of a dissolved or suspended constituent, per million parts by weight of water or other solvent, In dilute water solutions, one part per million is practically equal to one milligram per liter, which is the preferred unit.
pathogen – An organism which may cause disease.
ppm – The abbreviation for “part per million”.
precipitate – To cause a dissolved substance to form a solid particle which can be removed by settling or filtering, such as in the removal of dissolved iron by oxidation, precipitation, and filtration. The term is also used to refer to the solid formed, and to the condensation of water in the atmosphere to form rain or snow.