How do I use the MACHEREY-NAGEL visocolor HE Total Hardness H2 Test Kit to determine the total hardness of water? (MACHEREY-NAGEL Visocolor Hardness H2 Test Kit User Manual)

Answer

manuals.plus

Feb 22, 2025 - 03:35 AM

To determine the total hardness of water using the MACHEREY-NAGEL visocolor HE Total Hardness H2 Test Kit, follow these steps:

1. Rinse the test tube several times with the water sample you want to test and fill it up to the ring mark.

2. Add 2 drops of the indicator solution H2 to the test tube and shake it. The test sample should turn red. If the sample turns green, it indicates that the hardness is less than 0.05 °d.

3. Attach the plastic dropping tip onto the titration syringe. Press down the plunger and dip the tip into the titration solution TL H2. Slowly draw up the plunger until the lower rim of the black plunger O-ring aligns with the value 0 on the barrel scale. Note that the small air pocket below the plunger tip does not affect the determination.

4. Begin adding the titration solution dropwise to the test tube. It is recommended to hold the syringe in your left hand and the test tube in your right hand. Shake the test tube smoothly while adding the titration solution. As the red color starts to lighten, slow down the rate of addition until the solution turns completely green. You can easily observe the color changes by holding the test tube against a light background, such as a sheet of white paper.

5. Read off the total hardness in °d or mmol/L from the syringe barrel, specifically from the lower rim of the black plunger O-ring. If the first filling of the syringe is not sufficient to reach the color change (hardness > 2 °d), refill the syringe with titration solution TL H2 and repeat the titration. For each additional syringe filling used, add 2 °d to the total hardness reading.

Note: To express the result in °e (French degrees), multiply the result in German degrees by 1.25.

It is important to note that this method cannot be used for the analysis of sea water. If you have any specific questions or concerns about using this test kit in the presence of copper ions, please contact MACHEREY-NAGEL for special working instructions.

For more information on safety precautions, disposal of samples, and potential interferences, refer to the hazard warning, safety data sheet, and additional information provided by MACHEREY-NAGEL.