Diffuser for generating defined air bubbles as a measuring medium, and method for measuring the flow rate in liquids flowing slowly and with a free level

摘要

The invention describes a diffuser for generating defined air bubbles as a measuring medium for measuring the flow rate in slowly flowing bodies of water, and to an example of the application thereof. The diffuser according to the invention is characterised in that it consists of a restrictor having an opening cross-section of 0.002 mm2 to 0.785 mm2, which ends in a blind bore having a diameter of 1 mm to 8 mm and a length of 2 mm to 80 mm and preferably has a conical opening. The outside diameter of the conical opening amounts to 2 mm to 10 mm. The diffuser according to the invention can be used to form an adequate number of bubbles per time unit. The formation of bubbles is extremely uniform in terms of size and frequency.