HPLC Liquid Flowmeter

Digital HPLC flowmeters are used to measure the accuracy of High-Performance Liquid Chromatography pumping systems in order to meet FDA and other regulations regarding installation qualification (IQ), operational qualification (OQ) and performance qualification (PQ) of equipment used in the pharmaceutical and biopharmaceutical industries as well as other analytical labs. The process demands accurate, reproducible column retention time as an analyte is pumped through the HPLC system. These precision instruments are not to be likened to flow meters used on process lines measuring flow rates in, for example, thousands of gallons per minute but instead in fractions of milliliters per minute. Why Digital HPLC Flow Meters are Popular The answer is clear when compared to two alternative methods defined as volumetric using a finely graduated cylinder and gravimetric using a precision analytical scale. In either case a stopwatch is needed along with a technician with excellent eyesight and a high degree of patience. For volumetric measurement, technicians begin to collect HPLC eluent in the graduated cylinder and simultaneously start the watch. When sufficient volume is collected, the technician simultaneously stops the flow into the cylinder, stops the watch, then calculates and records the flow rate in milliliters per minute. For gravimetric, the process is similar but measured by weight of eluent captured in a tared container. These tedious, time consuming but critical process repeats over and over until a standard deviation can be calculated. Moreover, solvent evaporation collected in a graduated cylinder can throw off readings. How a Digital HPLC Flow Meter Works Contrast this laborious and error-prone approach with the FlowCal 5000 digital liquid flowmeter offered by Tovatech. Compact, portable and lightweight, it operates on the volumetric method and function by taking repeated and accurate measurements of the time it takes a solvent to pass through a small diameter tube.