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Pumps, Weigh Scales, And Thermal Mass Instruments All Have Limitations.
Until recently, the best technologies to measure and control small flows have had serious limitations, leaving researchers and process users little choice but to cobble together makeshift solutions to try to meet their needs.
Until QUANTIM, that is. QUANTIM is the first miniaturized Coriolis flow device that measures and controls mass addition directly, without regard to fluid properties or conditions. QUANTIM’s Coriolis technology plus integrated valve and PID control bring a new level of measurement accuracy and control to critical applications that require more precision and reliability than older technologies can provide.
Pumps Meter Volume, Not Mass.
Peristaltic Pump
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All pump users know that pumps operate by displacing a volume. In many cases, the mass of fluid added to a process or experiment is much more important than its volume. Equally, pump surfaces can degrade over time, further undermining assumptions that one might have made concerning the relationship between volume flow and mass flow. Finally, pumps need routine maintenance and calibration that require their periodic removal from service.
Weigh Scales Are Expensive And Cumbersome.
Weigh Scale
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Customers who desire the measurement of precision mass addition sometimes use a scale or balance to monitor loss of mass from the supply vessel. As with all precision gravimetric techniques, the scale must be isolated from environmental influences on the measurement, such as air drafts, temperature changes, and vibration, leading to an expensive and cumbersome system. Importantly, the instantaneous mass flow rate cannot be determined or controlled with a weigh scale system, merely the average mass flow rate over time.
Thermal Mass Can't Handle Process Variability.
Thermal Mass Flow
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Thermal mass flow devices have been used for decades in precision flow applications. For many users — particularly in gas applications — they work very well, provided that flow conditions are known and remain stable. But thermal devices operate on an inferred measurement which makes them susceptible to process variability. As fluid type, temperature, density, pressure or recipe changes, accuracy is reduced. Non-ideal gases, such as CO2 and hydrocarbon gases, are very difficult to measure with any reasonable accuracy using thermal devices. |
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