Hardness definition
Hardness means the amount of calcium and magnesium dissolved in water; measured by a test kit and expressed as parts per million (ppm) of equivalent calcium carbonate.
Hardness means the sum of the calcium and magnesium concentrations, expressed as calcium carbonate (CaCO3) in milligrams per liter.
Hardness means a measure of the calcium and magnesium salts present in water. For purposes of this chapter, hardness is measured in milligrams per liter and expressed as calcium carbonate (CaCO3).
Examples of Hardness in a sentence
Hardness tests shall be carried out on the parallel wall at the centre and a domed end of each cylinder or liner in accordance with ISO 6506.
Furnish aggregate non-friable, non-polishing, and conforming to the following requirements: Moisture Content <0.2% by weight ASTM C566 Hardness >6.5 Mohs Scale Fractured Faces 100% with at least one (1) fractured face ASTM D5821 Absorption ≤1% ASTM C128 Micro-Deval, max.
More Definitions of Hardness
Hardness means a characteristic of water which represents the total concentration of polyvalent cations (e.g., calcium, magnesium) expressed as calcium carbonate in mg/l. Hardness may be calculate for most waters by adding together the values obtained from multiplying the concentrations of calcium by 2.497 and magnesium by 4.116 to obtain the equivalent calcium carbonate concentration.
Hardness means the measure of calcium and magnesium salts in water expressed as dissolved calcium carbonate (CaCO3) unless otherwise noted.
Hardness means the sum of polyvalent cations dissolved in water. Cations are primarily calcium and magnesium although other metals such as iron, strontium, manganese, may contribute to hardness.
Hardness means a water quality parameter or characteristic consisting of the sum of calcium and magnesium concentrations expressed in terms of equivalent milligrams per liter as calcium carbonate. Hardness is measured in complianceaccordance with methods specified in 40 CFR 136, incorporated by reference in 35 Ill. Adm. Code 301.106.
Hardness means a measure of the calcium and magnesium salts present in water. For purposes of these regulations, hardness is measured in milligrams per liter (mg/L) and expressed as calcium carbonate (CaCO3).
Hardness means dissolved calcium and magnesium salts in water. Compounds of these two elements are responsible for most scaling in pipes and water heaters, and cause numerous problems in laundry, kitchen, and bath. Hardness is usually expressed in grains per gallon as calcium carbonate equivalent.
Hardness means a water quality parameter or characteristic consisting of the sum of calcium and magnesium concentrations expressed in terms of equivalent milligrams per liter as calcium carbonate. Hardness is measured in accordance with methods specified in 40 CFR 136, incorporated by reference in 35 Ill. Adm. Code 301.106. "Mixing Zone" means a portion of the waters of the State identified as a region within which mixing is allowed pursuant to Section 302.102(d) of this Part. “Thermocline” means the plane of maximum rate of decrease of temperature with respect to depth in a thermally stratified body of water. "Total Residual Chlorine" or "TRC" means those substances which include combined and uncombined forms of both chlorine and bromine and which are expressed, by convention, as an equivalent concentration of molecular chlorine. TRC is measured in accordance with methods specified in 40 CFR 136, incorporated by reference in 35 Ill. Adm. Code 301.106. "Toxic Substance" means a chemical substance that causes adverse effects in humans, or in aquatic or terrestrial animal or plant life. Toxic substances include, but are not limited to, those substances listed in 40 CFR 302.4, incorporated by reference in 35 Ill. Adm. Code 301.106, or any "chemical substance" as defined by the Illinois Chemical Safety Act [430 ILCS 45] "ZID" or "Zone of Initial Dilution" means a portion of a mixing zone, identified pursuant to Section 302.102(e) of this Part, within which acute toxicity standards need not be met.