Over the past 30 years, the use of digital measuring devices for determining and monitoring pH, acidity or acidity has grown substantially. pH measurement is not only done in laboratories, but is now also measured in the following industries: the environment, agriculture, horticulture, wastewater industry, the food industry, pharmaceutical and cosmetic industry, fish extraction, metalworking, education and everywhere where quality is important. This means that each application requires special tools, designed to suit individual needs and personnel with different backgrounds or training.