The basic concept of water hardness
Water hardness is the concentration of calcium ion(Ca2+) and magnesium ion (Mg2+). It is an important indicator of water quality.
Hazards of hard water:
(1) When hard water scales the boiler, it will waste heat energy and even cause an explosion.
(2) Hard water can not be used in the process of many industries such as pharmaceutical, eletronics, paper, printing, chemical, printing&dyeing, food, beverage industry and etc.
(3) Hard water is extremely harmful to human life and health
mmol/L-the basic units of water hardness | mmol/L (Boiler)-the special units of the water hardness of industrial |
mg/L (CaC03)-CaC03 mass concentration indicates water hardness | * fH – France |
mg/L (CaO)-CaO mass concentration indicates water hardness | * dH – German |
mg/L (Ca)-Ca mass concentration indicates water hardness | * EH – England |
EDTA volumetric method
1 Inconvenient preparation of reagents, complication and uncertain and uncertain final result.
2 Lower limit of testing less than 5 mg/L(CaC03)*
Colorimeter method
(1) Sub-range test, preparation of three regents of low, medium and high hardness required.
(2) Lower limit of testing less than 50 mg/L(CaC03), low accuracy
(3) Compilcated operation, a cuvette, a pipette and detergnt required.
Features of electrode method
-Employ model 601-F water hardness combination electrode which consists of measurement electrode, reference electrode and temperature probe. Equal selectivity for the calcium and magnesium ions in water samples. New strucre, stable electrode potential, quick response and easy to use.
-The electronic unit adopts intelligent chip design, with automatic calibration. Automatic temperature compensation, automatic swithes of range, data storage and etc.
-Easy to operate, measurement range 0-10 mmol/L
-Ability to switch among eight unit: mmol/L, mg/L(CaO), mmol/L(Boiler), mg/L(Ca), *fH, *dH and *EH.
-Equipped with B1, B2 and B3 calibration solutions.
-RS232 out-put in Moad YD200 Laboratory Water Hardness Meter, matching the computer.
-Waterproof design of Model YD300 Portable water Hardness Meter (Waterproof IP57), equipped with a portable case.
Mode | Model YD200 Lap. Water Hardness Meter | Model YD300 Portable Water Hardness Meter |
Range | 0-10 mmol/L or 0-1000 mg/L (CaC03) | |
Resolution | 0.01 and 0.1 water hardness units | |
Accuracy | ±5% full scale | |
Units | mmol/L, mg/L(CaC03), mg/L(CaO), mmol/L(Boiler), mg/L(Ca). *fH, *dH and *EH | |
Temperature compensation | 5 to 50˚C (automatic or manual) | 5 to 50˚C (automatic) |
Communication Connector | RS-232 out-put, equipped with communication sofeware and cable | None |
Electrode | Mode 601-F water hardness combination electrode | Mode 601-S water hardness combination electrode |
Calibration Solution | B1, B2 and B3 one bottle each (250mL) | B1, B2 and B3 one bottle each (100mL) |
Electrode HolderData Storage | Mode 601 stirring type electrode holder | None |
Data Storage | 128 groups | 99 groups |
Power | DC9V power adaptor | 2 x AA batteries (1.5 V x 2) |
Dimension and weight | 160 x 190 x 70mm/750g | Portable Case: 255 x 210 x 50mm/790g |