Development Of Multi-parameter Detection System For Biological Safety Cabinet

Biological safety cabinet is the protective equipment which can providethe first physical isolation for people, environment and experimental samples.Cabinet leakage, inflow air and down-flow air velocity are the core evaluatingindicators of biological safety cabinet. Most of the biological safety cabinetparameter detection equipment is only for a single parameter and can’t apply to classI~III bio-safety cabinets, and manual methods are mostly used in, which can notrealize high efficiency and accuracy. This paper proposes a split type ofmulti-parameter automatic detective system which contains master-slave units. Themaster is mainly based on microcontroller with the automatic inflation and pressuredetection realized. By Automatic adjustment of the two-axis motion mechanismcombining with airflow velocity sensor, the measuring point positioning and airflowvelocity testing can be realized in the slave. Consequently, the master-slave unitsachieve data interaction and information transfer through wireless communication.The main research contents of this paper include:1. The biological safety cabinet parameters detection system was designedbasing on the research of parameter test method and detective system situation athome and abroad, meeting the need of portability, multi-parameters and compatibility.According to the fact that inner flow field disturbance can be caused easily bybuild-in slave unit, a simulation model of the disturbance was designed and theinfluence from geometric dimensioning of the salve unit on the inner flow field wasanalyzed.2. According to the demands of confined space precision gas-filling and airflowvelocity multipoint measurement, the inflatable structure and air path controlmechanism was designed. The mechanical structure’s design and realization werediscussed emphatically.3.The system hardware design and key components selection were completed,which included the detailed design such as the high-performance and stable powersupply module, microprocessor modules, motor control module, real-time communication module and sensor module. Software design was accomplished withmodularity. The multi-parameter detection system was analyzed in variousparameters test and data error.Statistics show that the accuracy of pressure detection is±5Pa in the range of0~1000Pa, and the accuracy of airflow velocity testing is3%FS. This biologicalsafety cabinet multi-parameter detective system solves many problems biologicalsafety cabinet on market have, such as lack of measuring parameter, poor real-timeperformance, low measurement accuracy and so on.