Flowmeters, mass inferential

General Principles There are two main types of mass flowmeters (1) the so-called true mass flowmeter, which responds directly to mass flow rate, and (2) the inferential mass flowmeter, which commonly measures volume flow rate aud flmd density separately. A variety of types of true mass flowmeters have been developed, including the following (a) the Maguus-effect mass flowmeter, (b) the axial-flow, transverse-momentum mass flowmeter, (c) the radial-flow, transverse-momentum mass flowmeter, (d) the gyroscopic transverse-momentum mass flowmeter, aud (e) the thermal mass flowmeter. Type b is the basis for several commercial mass flowmeters, one version of which is briefly described here. 

Inferential Mass Flowmeter There are several types in this category, including the following ... 

Finally, there is an opportunity to calculate pH online for tlie flat part of a titration curve if there are coriolis flowmeters to accurately measure the mass flow and density of two component mixtures or streams with sufficiently constant acid and base concentrations. An inferential measurement or pH estimator based on an online titration or charge balance model can become a third measurement that enables middle selection. In one application, it was found that the calculation was more accurate than the electrode readings because of the flatness of the titration curve. A single coriolis flowmeter on each of the influent and reagent... 

The principal advantages of this mass flowmeter in cryogenic service is that it requires no moving parts in the fluid stream, requires no flow straighteners, and can be used with two-phase flow. Its major disadvantage is that it is an inferential mass flow measurement with slow response time. Additionally, the screen and honeycomb open area may be insufiicient to allow free passage of solid particles. 

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