Hard Water Testing
Hard Water Testing - Related Videos
08:01
Rockwell Hardness Test and the Effect of Treatment on Steel
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2023
Source: Roberto Leon, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA Hardness testing is one of the most universally valuable mechanical tests available to engineers, as it is both simple and relatively inexpensive for the wealth of information and data it produces. Hardness testing, generally in the form of a surface penetration test, is both quicker and less destructive than tensile testing. Hardness provides a linear relationship with tensile strength over a...
07:47
Shallow Water (Paddling) Variants of Water Maze Tests in Mice
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Cited by 22 •
2013
Mice can swim, but many strains appear to find this activity stressful. To overcome this problem mazes have been devised where escape from shallow water is used to motivate behaviour. These have been demonstrated to support learning at least as good as the traditional and widely used Morris water maze.
01:14
Testing Water Quality
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2024
When the quality of water for concrete preparation is uncertain, its impact on the setting time of cement and compressive strength of mortar is assessed by comparison with de-ionized or distilled water benchmarks. American Society for Testing and Materials (ASTM) C1602 requires the setting times to be within 90 minutes of the control, British Standard (BS) 3146:1980 allows a 30-minute variance in the initial setting, while British Standards European Norm (BS EN) 1008 specifies initial setting...
10:24
Morris Water Maze Test: Optimization for Mouse Strain and Testing Environment
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Cited by 57 •
2015
This manuscript describes a Morris water maze (MWM) protocol tailored for use with a commonly used mouse model of Alzheimer's disease. The MWM is widely used in transgenic mouse models. Implementation of a procedure sensitive to the background strain of the mouse model is essential for detecting group differences.
08:21
Quantitative Hardness Measurement by Instrumented AFM-indentation
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Cited by 6 •
2016
This experimental protocol describes how atomic force microscopy can be used to measure hardness at the true nanometer scale and to detect single atomistic plasticity events.
FAQs
The pH 10 buffer creates the chemical conditions needed for the indicator and EDTA to interact consistently with dissolved calcium and magnesium ions. Maintaining this condition helps produce a clear, reproducible endpoint when the indicator changes color. Without controlled pH, the measured hardness could be less reliable and difficult to compare among samples.
EDTA binds dissolved calcium and magnesium ions in stable complexes with a 1:1 stoichiometric relationship. As standardized EDTA is added, the volume required to reach the indicator endpoint corresponds to the quantity of these hardness-producing ions present. This relationship allows the titration result to be converted into a quantitative hardness value.
The indicator provides a visible signal that the titration has reached its endpoint. It is added after the sample is buffered, and its color changes as EDTA binds the dissolved metal ions under the selected conditions. Observing this transition tells the analyst when enough standardized EDTA has been delivered for calculation.
A typical workflow begins by preparing the water sample, adding a buffer near pH 10, and treating it with an indicator. Standardized EDTA is then added until the indicator shows the endpoint. The amount of EDTA used is interpreted through its 1:1 binding with calcium and magnesium, and the result is reported as calcium carbonate equivalents.
Reporting results as calcium carbonate equivalents places different samples on a common comparison scale, even though the measured ions are calcium and magnesium. This convention makes it easier to compare water sources, assess changes during treatment, and communicate hardness measurements consistently across household, laboratory, and industrial monitoring contexts.
The analysis provides a way to monitor dissolved calcium and magnesium associated with mineral scale formation. Tracking reported hardness values helps maintenance teams evaluate water conditions relevant to boilers and cooling systems. Results can support comparisons over time and indicate whether treatment practices are changing the hardness of the water entering these systems.
Hardness testing can compare a water sample before and after a softening or treatment process. Because results are expressed as calcium carbonate equivalents, changes can be assessed using the same reporting basis. The method therefore helps determine whether household treatment is reducing the measured calcium and magnesium content associated with hard-water effects.