HARD-406 Water Hardness Sensor
The Apure HARD-406 all-in-one on-line total hardness sensor uses a PVC membrane based calcium and magnesium ion selective electrode to test the total hardness of water (in terms of CaCO3), with temperature compensation to ensure that the test is fast, simple, accurate and economical.
- Stable performance
- Quick installation
- Long life
With Apure’s calcium and magnesium ion selective electrodes, the internal reference solution exudes extremely slowly from the microporous salt bridge at a pressure of at least 100 KPa (1 Bar). Such a reference system is very stable and the electrode life is longer than that of ordinary industrial electrodes. 3/4 NPT pipe thread for easy countersunk installation or mounting in pipes and tanks.
Working principle
Digital Water Hardness Sensor is a sensor based on the potentiometric method for measuring water hardness. It mainly consists of a measuring electrode, a reference electrode and a temperature electrode.
The measuring electrode is usually an ion-selective electrode with selective response to calcium ions (Ca2+) and magnesium ions (Mg2+). The electrode surface undergoes an ion exchange reaction with calcium and magnesium ions in the aqueous solution to form the electrode potential. The electrode potential is logarithmically related to the activity of calcium and magnesium ions in the aqueous solution, and the total concentration of calcium and magnesium ions in the aqueous solution, i.e., the water hardness, can be calculated according to the Nernst equation.
The role of the reference electrode is to provide a stable reference potential. Commonly used reference electrodes include silver/silver chloride electrodes and calumel electrodes.
Temperature electrodes are used to measure the temperature of an aqueous solution. Since temperature affects the electrode potential, temperature compensation is required to obtain more accurate measurements.
Advantages
- High measurement accuracy and sensitivity.
- Fast response and short measurement time.
- Easy to use and easy to maintain.
- Continuous on-line monitoring can be achieved.
Applications
- Industrial Wastewater
- Drinking water
- Surface water
- Boiler feedwater
- Condensate and cooling water
- Process water
| Brand | Apure |
|---|---|
| Model | HARD-406 |
| Measuring range | 0-1000.0mg/L |
| Resolution | 0.1mgL, 0.1℃ |
| Accuracy | ±10% FS, ±0.3℃ |
| Current output | RS-485 (ModbusRTU), 4-20 mA (optional) |
| Temperature | 0～40℃, ≤0.2MPa, pH:4～10 |
