Durognost Special Buffer Solution is a solution designed to buffer highly alkaline water samples, ensuring that analyses can be carried out reliably. For accurate analyses at high pH levels The Durognost Special Buffer Solution is a buffer solution for alkaline water samples. It is used to buffer strongly alkaline water samples (above pH 10) for the determination of total and residual hardness using Durognost and Duroval test kits. The contents of the bottle are sufficient for approx. 200 analyses. The Durognost Special Buffer Solution stabilises highly alkaline water samples and brings the pH value into a range that allows for accurate measurement. What is the buffer solution suitable for? The solution is not suitable for calibrating pH meters or as a general pH standard solution, but is used exclusively for buffering highly alkaline water samples. What is the buffer solution used for? Our buffer solution is used to adjust highly alkaline water samples (often with a pH value above 10) to a defined, lower pH value prior to titration or analysis, and to maintain this value. This is important for accurate measurement results, particularly when determining total and residual hardness, for example using DUROVAL® and DUROGNOST® test kits. Applications of the buffer solution The buffer solution is used wherever highly alkaline conditions would interfere with standard testing procedures. It facilitates accurate measurements by lowering the pH to a measurable range.

The DUROGNOST® I (0–0.1 °dH / 0–2 ppm / 0.2 °F) powder test kit is designed for the rapid colorimetric determination of residual hardness in water. Analyses: approx. 700 Indicator for determining residual hardness in water Special indicator in powder form for the rapid colorimetric determination of the slightest traces of hardness in the range of 0–0.1 °dH or 0–2 ppm CaCO₃ or 0.2 °f (French hardness). Complete with measuring tubes and dosing spoon. With the Durognost I Powder Limit Test Kit, you can easily determine whether your water exceeds a specific limit value. The kit uses a powdered indicator that reacts when mixed with water. The test kit is suitable if you want to check quickly and without complicated measurements whether water is harder than a specified value. It is not suitable if you require exact numerical values for water hardness. Easy water hardness testing The test kit uses a chemical indicator that changes colour depending on the threshold value reached. This gives you a clear result without the need for any equipment. How do I use the indicator? Dissolve 50 mg (one level measuring spoon) of DUROGNOST I indicator in 10 ml of practically completely softened water. The resulting colours correspond to the following values: Green colour: 0 °dH Grey colour: approx. 0.025 °dH Violet-tinged grey colour: approx. 0.05 °dH Red colour: approx. 0.1 °dH and above

The Durognost SR Threshold Test Kit is a simple set for quickly checking whether water hardness levels fall within the range of 0.25 to 0.5 °dH. Check water hardness quickly Special liquid indicator in a dropper bottle for monitoring residual hardness in softened water, calibrated to the limit values of 0.5 and 0.25 °dH (8.9 and 4.47 ppm). With the Durognost SR kit, you can easily determine whether your water falls within this very soft hardness range. The indicator powder changes colour as soon as the water hardness limit is reached or deviates from it. This gives you a clear result quickly. This set allows for approximately 250 analyses. The kit is only suitable if you wish to check whether the water hardness is very low. If you require exact numerical values, this kit is not suitable. Quick test without laboratory equipment First, rinse the measuring tube with the water sample. Then fill the tube with the water sample up to the 5 ml or 10 ml mark. Add one drop of indicator and mix it thoroughly with the water sample by gently swirling the tube. After approx. 30 seconds, the water sample will change colour. Water sample colour: Green = softened water is fine Red = Regenerate the water softener Please note: When comparing the result with the enclosed table, it is essential to take the selected sample volume (5 ml or 10 ml) into account. Please read the enclosed instructions for use carefully before use.

Durognost SR 0 (0.1/0.05 °dH) Threshold test kit for the rapid determination of residual hardness. Threshold monitoring in the very low hardness range Special liquid indicator in a dropper bottle for monitoring the residual hardness of softened water, calibrated to the limit values of 0.1 and 0.05 °dH (1.79 and 0.89 ppm). Complete with measuring tubes and stoppers. Sufficient for approximately 250 analyses; the required measurement time is approx. 30 seconds. Identification of the hardness range When the indicator comes into contact with the water sample, it changes colour as soon as the specified limit values of 0.1 °dH or 0.05 °dH are reached or exceeded. How should the reagent be used? Please rinse the supplied measuring tube with the water sample. Then fill the measuring tube with the water sample up to the 5 ml or 10 ml mark. Add one drop of indicator and swirl the tube to dissolve it completely in the water sample. After a reaction time of approximately 30 seconds, the water sample will change colour. Water sample changes colour: Green = softened water is fine (within the defined range) Red = Regenerate the water softener Please read the supplied instructions for use before use.

The Durognost SR 1 Limit Value Kit is a simple set for quickly monitoring residual hardness in softened water, calibrated to limit values of 1 and 0.5 °dH. Water hardness limit value test for simple checks Special liquid indicator in a dropper bottle for monitoring residual hardness in softened water, calibrated to the limit values of 1 and 0.5 °dH (17.9 and 8.9 ppm). The kit comes complete with test tubes and stoppers and allows for approx. 250 analyses. The colour change of the indicator shows whether the water sample is within or outside the limit value. How does the test work? First, rinse the measuring tube with the water sample. Then fill it with the water sample up to the 5 ml or 10 ml mark. Add one drop of indicator and mix it thoroughly with the water sample by gently swirling the tube. After about 30 seconds, the water sample will change colour. Water sample colour: Green = softened water is fine Red = regenerate the water softener Please note: When comparing the results with the enclosed table, it is essential to note the sample volume used (5 ml or 10 ml). Please read the enclosed instructions for use carefully before use.