If we're thirsty, we can turn on the tap in this country and drink without thinking. We've become accustomed to doing so and easily forget that we only share this privilege with a fraction of the world's population. The high quality of the drinking water in Germany is ensured by the Drinking Water Ordinance that among other things prescribes regular microbiological monitoring. The Lake Constance Water Supply (BWV) Authority that supplies 320 communities with about 4 million residents with drinking water from Lake Constance uses a BINDER KB 240 refrigerated incubator.
The water is taken from Überlinger See, a section of Lake Constance between Sipplingen and Überlingen. It comes from a depth of 60 meters and is 5°C. The untreated water, which is already very pure, is prepared using microstrainers, ozone and sand quick filters. The smallest algae and suspended solids are removed, microorganisms such as bacteria and viruses killed or inactivated and the water completely freed of suspended matter. In recent years, the BWV has supplied, prepared and pumped on average 4,100 liters of untreated water per second to the transfer containers of association members.
To ensure quality, more than 500 microbiological analyses are performed each week. Laboratory personnel test the water taken from the pipeline system at various locations for Escherichia coli, coliform bacteria, enterococci, clostridium perfringens and pseudomonas aeruginosa. The colony counts are ascertained at 20°C and 36°C within a period of 48 hours. Even the smallest changes in the quality of the drinking water can be detected in this manner.
For the laboratory team under the direction of Dr. Jürgen Meyer, safe and reproducible incubation, rapid loading and unloading of the incubator and protection of the microorganisms against overheating or undercooling are particularly important. Short reset times are also important because the incubator doors are opened about 10 times per day to load and unload. Medical Technical Assistant Elke Kramer at BWV explains that "the BINDER refrigerated incubator ensures safe and reproducible incubation of microbiological samples even at temperatures below ambient temperature." In particular, Elke Kramer lauds the homogenous test conditions of the BINDER KB 240 when loaded and its precision. The BINDER unit owes both to the electronically controlled APT.line(TM) preheating chamber technology and the DCT(TM) refrigeration system, which accurately ensure homogeneous temperature distribution even when fully loaded and to tenths of a degree.
The laboratory team also emphasizes the inner chamber design that BINDER owes to its know-how in series production. The inner chamber is a beading boiler and the interior fittings can be completely removed for easy cleaning. The relatively low noise level of the unit and wear-resistant surface of the housing are also described as pleasant.
Apart from microbiology, the cooling incubators of the BINDER KB series, for example, are also used in biotechnology, the food and beverage industry and for studying plant and insect growth. The optional supplementary equipment also includes the BINDER Data Logger Kits for independent recording of the temperature data and standard software developed by BINDER for seamless, standards-compliant documentation of all test results.