A Design Of Image Acquisition Instrument Forbacterial Culture Detection

With criminals counterfeiting means increasedin recent years, food safety incidents happened frequently, the importance of microorganisms such as e. coli has also improved.In this paper, an instrumentused for paper strip method was designed. It can culture the bacteria and acquisition image. Use the paper to collect Escherichia coli on the tableware under test, put them in the incubator to thermostatic cultivation, through the paper image information and color reaction to quantitative and qualitative analysis of the health situation of tableware.1)The detectionsetused for bacterial culture and image acquisition is divided into five parts: the body shell parts, power supply, computer parts, temperature detection, image acquisition part. The whole three-dimensional model was established byusing software Pro/Engineer. According to the characteristics of various modules and the different function, carry on the design and model selection respectively. Finally integrating each module and compared with the overall design scheme, each module of insufficient place should be modified and optimized.2)Focused on the existing problemsof detecting bacterial colonies on tableware and kitchenware, a novel constant-temperature incubator for the paper strip method was designed, and the associated temperature-control system was developed. Firstly, the detection method and working principle of the incubator were described, and the temperature-control system was designed. After determining the temperature-control principle, the heater band made up of the insulating multi-layer alkali-free material was selected and uniformly wrapped around the liner in a clockwise direction. Three types of temperature sensors were compared. With stability and accuracy taken into consideration, a platinum resistor was chosen and installed at the central position of the back wall of the liner. Additionally, an electronic temperature controller was selected. Accordingly, the constant-temperature incubation and image acquisition system were integrated in the developed incubator. After the equipment was assembled and testing was complete, the incubator was able to detect temperature accurately, reliably, and conveniently in real time by which the hygienic conditions of tableware could be detected rapidly and effectively.3) Image acquisition module of the incubator through count coliform group image grey value of the paper, the system can be quickly detected coliform bacteria and identify the number of coliform group, to determine the health conditions of tableware.MATLAB software is used to calculate the image gray mean and standard deviation of arithmetic average and poor calculation further.The structure of the lighting system is verified by the orthogonal experiment design, the optimum parameter of the picturewas determined.