Microbial limit tester is a device used to detect the microbial content in samples, widely used in industries such as food and cosmetics. Its core principle is membrane filtration method: microorganisms in the sample are trapped on the filter membrane through negative pressure filtration, and then cultured and counted. The model adopts a diaphragm pump design, without the need for external filter bottles, supports synchronous processing of multiple filter membranes, and has wet heat or flame sterilization functions, effectively avoiding cross contamination.
structural composition
Power system: Imported diaphragm liquid pump is usually used, providing a filtration flow rate of 500-1500ml/min. Some models support independent control of multiple filter heads.
Filter component: composed of a filter cup and a filter head. The filter cup is often designed with a lip seal to eliminate leakage risks, while the filter head is usually designed with a groove to enhance operational safety. It is compatible with two standard filter membranes, 47mm and 50mm.
Control system: mostly touch screen interface, can display working status, some models are equipped with SIP one click cleaning and disinfection function.
Body Material: The main body of the device is made of 304 or 316 stainless steel, and the casing is polished with a mirror finish for easy cleaning.
core functionality
Negative pressure filtration: A negative pressure environment is created through a vacuum pump or a built-in diaphragm liquid pump to quickly pass the test solution through the filter membrane.
Sample filtration: Under negative pressure, the liquid sample to be tested is filtered through a microporous membrane. Microorganisms or solids smaller than the micropores of the membrane are trapped on the membrane, while the liquid is discharged through the membrane.
Filter membrane transfer: Use a membrane extractor to remove the filter membrane that has retained microorganisms, and place its bacterial surface flat on the pre prepared solid culture medium.
Closed cultivation: Cover the lid to form a closed cultivation box, place the box in a constant temperature incubator, and allow bacteria or fungi to grow under appropriate temperature and humidity conditions. The cultivation time is generally 24-48 hours.
Microbial Counting: After cultivation, count and analyze the microorganisms in the culture dish. By counting the number of bacteria or fungi, the limit of microorganisms in the sample can be determined.