microtest RH 5 Residual Hardness
 |
microtest RH 5 Residual Hardness
for the determination of residual Total Hardness; limit = 5 mg/L
Replacement reagents:
1 reagent (Indicator) ... $28.50 + GST (availability: 3 - 4 days)
|
Product Details
| Product Code | 609200 |
| Contents | Indicator, 15 mL Cuvette, 4 mL Instructions for Use |
| Analytical Method | Complexometric Titration: At pH = 10, earthalkali metals (calcium, magnesium and strontium) form a pink coloured complex with certain indicator dyes (e.g. eriochrome black T, calmagite). On adding EDTA (ethylenediamine tetraacetic acid), these metals prefer to complex with EDTA, and release the indicator dye. As the uncomplexed dye exhibits a blue colour, the titration endpoint is indicated by a sudden colour change from pink to pure blue. The amount of EDTA added is directly proportional to the concentration of Ca2+, Mg2+ and Sr2+ ions. Results are expressed as calcium carbonate CaCO3.
This kit used a mixed Buffer/Indicator/Titration Solution, one drop of which on a 2 mL water sample indicates whether the threshold of 5 mg/L has been exceeded: colour blue: residual hardness is less than 5 mg/L colour red: residual hardness is greater than 5 mg/L |
| Number of Tests | 400 |
| Interferences | Other metals like Al, Fe, Mn or Cu interfere by complexing the indicator dye and not releasing it any more. The indicator becomes "blocked" and a colour change at the titration endpoint does not occur. |
| Measuring Range | This test does not have a measuring range, but indicates whether the residual of total hardness exceeds the threshold of 5 mg/L. |
| Shelf Life | 2 years |
| Applications | Monitoring of residual total hardness levels in softened and R/O water (boiler feed water). |