微小液体流量校准技术

Calibration technique of micro-liquid flow

微小液体被广泛应用于微反应器中,具有传热传质效率高、高通量、集成化、方便控制等优势,微小液体流量计可以实现对样品的精确控制,但在极低流量下(μL/min乃至nL/min),微小液体流量计存在计量基标准不完善、校准难度大等问题。本文综述了目前在微小液体流量计量领域所采用的几种校准技术,主要包括质量法和体积法,并根据现有的研究给出了这些技术目前所能达到的校准范围和不确定度。分析表明,现有的质量法微小液体流量校准技术在应用于微小液体时仍具有不足,需要进一步研究多种作用机制的影响;体积法微小液体流量校准技术有多种实现方式,虽然目前仍处于探索阶段,但在未来有望成为更具有研究前景的一种方法。最后,结合微小液体流量计量技术的发展和先进测量体系的建设,展望了微小液体流量计量的发展前景。

Micro-liquid flow is widely used in microreactors,which has the advantages of high heat and mass transfer efficiency,high throughput,integration,and easy control.Micro-liquid flowmeter can achieve accurate control of samples.At meager flow rates(μL/min to nL/min),however,micro-liquid flowmeter has problems such as incomplete measurement standards and difficult calibration.Several calibration techniques used in the field of micro-liquid flow measurement are summarized,including the mass method and volumetric method.The calibration range and uncertainty of these techniques are given according to the existing research.The analysis shows that the current mass method calibration technology is still insufficient in the application of micro-liquid flow,and the influence of multiple action mechanisms needs to be further studied.The volumetric method can be achieved by different means.Although this method is still in the exploration stage,it is expected to become a more promising method in the future.Finally,combined with the development of micro-liquid flow measurement technology and the construction of an advanced measurement system,the development prospect of micro-liquid flow measurement is forecasted.