Most of the detergents used in professional cleaning services, including catering facilities, are supplied as concentrates which are diluted before use in the exact proportions due to the manufacturer's recommendations. To simplify the preparation of aqueous solutions of detergents are generally used dispensers which provide compliance with the exact proportions during the process of dilution and the use of cleaning chemicals. Dispensing equipment is widely used in catering. Thus, in different types of dishwashers (conveyor, door type, etc.) are used one or more types of dispensers for rinsers and detergents. Herewith, dispensers of small capacity dishwashers (door type or front loading) are equipped with sensor pump which injects the detergent at the beginning of the washing cycle and adds the predetermined amount of it at the beginning of each washing cycle. In such types of dishwashers is provided such type of dispenser which has a conductivity sensor determining the concentration of detergent in the water on the basis of conductivity data.