Research On Liquid Micro-flow Metrology Standard Device For Biomedical Field

With semiconductor manufacturing industry, biological engineering,medicine and chemical industry rising, the flow metrology is to the low end of theextension, small flow and micro-flow metrology demand highlights up gradually. Formicro-fluidics research and the needs of small flow metrology accuracy is alsocausing more and more attention of scientists, and small liquid flow metrology hasbecome a much-needed field current metrology of fluid metering technologies. Thisarticle focuses on the service in the field of biomedical micro-liquid-flow metrologystandard device has been studied how to design the entire system and PC hardwareverification system and to achieve a range of flow rate10mL/h~1000mL/h inside theglass tube flowmeters, Coriolis and thermal mass flow meters, infusionpump/injection pump and infusion pump calibrated detector test, etc.. This papermainly do the following research work:First, by analyzing the flow range of10mL/h~1000mL/h in the Coriolis andthermal mass flow meters, infusion pump/injection pump and the flow detectiondevice characteristics, made a complete test system is divided into active andnon-slip source verification test separately the two parts of the test method, and thecorresponding mathematical model, which is the active branch for injection pumpsand infusion pumps were seized with the fluid source object, the passive branch fordivisions and the thermal mass flow meters, glass tube flow meter so there is nosource of fluid was seized objects. Passive branch is based on the piston principle ofthe test method, using a combination of PLC and LabVIEW control program. Second,the biomedical micro-flow metrology standard device hardware architecture aredescribed, the device uses standard piston structure to stepper motors as actuators,ball screw-driven piston movement by providing standard flow source. Finally,according to the certification requirement was seized components developed underthe corresponding position control system and PC test system. Under the positioncontrol system with PLC as the core, in order to achieve motion control, valvecontrol, and analog data acquisition functions; PC test system using LabVIEWgraphical programming platform designed for the realization of human-computer interaction, test automation, data show, data storage and report printing.Through experimental research, the set of standard device has a good testperformance, development of test systems friendly interface. Unit expandeduncertainty (0.5~1.0)%(k=2), test repeatability better than0.032%, and highprecision electronic balance to achieve consistent performance results than0.124%.Currently, the device has been put into use, running in good condition, can test theflow range of10mL/h~1000mL/h for infusion pumps, syringe pumps and other fluidsource have been seized objects and glass rotor flowmeter, infusion pumps and othernon-detector fluid source object was seized for examination.