Design of a Constant-Temperature Incubator for Paper Strip Contamination Detection

摘要

Currently, hygienic conditions of public tableware and kitchenware have become a hot social concern. This work aimed at solving existing problems in detecting the presence of bacteria, a constant-temperature incubator for the paper strip method was designed and a related temperature-control system was developed. Firstly, the detection method and working principle of the incubator were elaborated upon. Using a paper strip, Escherichia coli (E. coli) was collected from the tableware to be examined. The paper strip was then placed in the incubator for a constant-temperature culture. Through chromogenic reaction, the hygienic condition of the tableware could be qualitatively and quantitatively assessed by analyzing the image information on the paper strip. Subsequently, with regard to the heater band, a wrapping pattern was designed and a suitable material was chosen. Three types of temperature sensors were compared, and a platinum resistor was finally selected and installed at the proper position. Additionally, an electronic thermostat was chosen. Conclusively, the designed incubator, which integrated the constant-temperature culture and image acquisition system, could detect the temperature accurately, reliably, and conveniently in real time, and could also detect the hygienic condition of public tableware rapidly and effectively.