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. 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

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.

Titration kit for the determination of carbonate hardness via complexometric titration 1 drop corresponds to 1 carbonate hardnessAnalyses: approx. 30 (at an average hardness of 10 °KH)   This product is available in following versions:  1 pcs.50 pcs. 

The Duroval C test kit is an analysis kit for determining the carbonate hardness of water samples. It delivers reliable results within a few minutes. Measuring carbonate hardness – a practical solution With the Duroval C test kit, you can determine the carbonate hardness or the m-value (acid capacity up to pH 4.3; KS 4.3) in natural and technical water samples by titration using a liquid titrant and a dosing pipette precisely calibrated in °dH and mmol/l. Complete with measuring tubes, dosing pipette calibrated to 0–20 °dH and 0–7 mmol/l, special connecting stopper, indicator and 50 ml titration solution. This allows for up to approx. 100 analyses to be carried out at an average carbonate hardness of 10 °dH. The measurement time is approx. 2 minutes and the measurement accuracy is 0.5 °dH. How the measurement works Pour the water into the test tube, then add the titration solution drop by drop using the pipette, observing the colour change as you do so. Once the chemical endpoint is reached, you can read the carbonate hardness value in °dH or mmol/l.

DUROVAL® CPM Test Kit – Quickly Determine Carbonate Hardness & Acid Capacity Set for determining carbonate hardness, p-value, and m-value. The Duroval CPM Test Kit is designed to measure carbonate hardness (m-value; acid capacity up to pH 4.3; Ks 4.3) and p-value (acid capacity up to pH 8.2; Ks 8.2). The kit provides precise results within minutes and enables straightforward analysis. Contents of the DUROVAL® CPM Test Kit Measuring tubes Calibrated dosing pipette 0–20 °dH and 0–7 mmoI/I Special connection stopper Indicators for p-value and m-value 50 ml titration solution Precise determination of carbonate hardness, p-value, and m-value by titration The DUROVAL® CPM Test Kit is a professional analysis set for determining carbonate hardness and water acid capacity. It allows the measurement of p-value (Ks 8.2) and m-value (Ks 4.3), providing essential parameters for the evaluation of raw, process, and operational water. Using the proven titration method, users obtain fast and reliable results in just a few minutes. The kit is ideal for applications in water treatment, industrial processes, and technical operations. Advantages of the DUROVAL® CPM Test Kit for Water Analysis The DUROVAL® CPM Test Kit excels with easy handling and high measurement accuracy. The calibrated dosing pipette ensures precise titration, while the special indicators provide clear and easily visible color changes. The compact kit is ideal for mobile measurements, service operations, and routine checks. It provides a reliable manual solution to quickly assess carbonate hardness and acid capacity and ensures safe control of water chemistry processes. Frequently asked questions How long do Heyl chemicals last? The shelf life is printed on the label of each product. Upon delivery, the guaranteed shelf life is at least 7 months. Can Heyl reagents also be purchased individually? That depends on the specific item to be ordered. For Testoval products, only the complete refill pack can be ordered. The individual small bottles cannot be reordered separately. For the Duroval test kit, the individual components of the refill pack can also be reordered separately. Can the indicator and titration solution be purchased separately? Yes, this is possible for the Duroval product range. Where can I find the safety data sheet? The safety data sheet can be found directly with the product in our shop or separately in the download area under the relevant heading. How can the chemicals be disposed of? Disposal instructions can be found in section 13 of the safety data sheet. Disposal must be carried out in accordance with official regulations. Can the chemicals still be used after the expiry date? No, the chemicals can no longer be used after the expiry date. After the expiry date, accurate measurement results can no longer be guaranteed. How should Heyl chemicals be stored? Section 7 of the safety data sheet contains all relevant information on the storage of chemicals. The recommended storage temperature should be between 15-25°C.