process variable


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process variable

[′prä‚ses ‚ver·ē·ə·bəl]
(chemical engineering)
Any of those varying operational and physical conditions associated with a chemical processing operation, such as temperature, pressure, flowrate, density, pH, viscosity, or chemical composition.
References in periodicals archive ?
The effect of process variables on product responses are shown in Table 3.
Three process variables in caulking were set up as design variables.
In this way, the contribution of each original process variable [q.sub.i] to the certain fault is measured.
Previous research generally focused on the effect of a single input factor on a single process variable. However, in addition to its obvious direct effect on a particular process variable, a single input factor can have (a) considerable indirect effects on several other process variables and (b) direct effects on more than one process variable.
For example, for process variable i = 136 then cc(i) is mathematically equivalent to the sample correlation of the "Core Resin Pressure" with IB.
The conclusion is the foaming time is a relatively poor process variable for controlling cell growth and the cell size for both amorphous and semicrystalline polyesters for foaming times greater than 2 and 10 s, respectfully.
Dual four-digit LED displays for setpoint and process variables. Inputs include thermocouple, RTD, current, and voltage.
"Model predictive" means that the controller predicts its future manipulations to ensure that process variables remain within pre-defined constraints.
Two process variables, such as melt temperature and pressure, can be shown on digital display indicators.
These three rosins were categorized as having low, medium, and high fortification, and the level of fortification represented a fifth process variable for these rosins.
If the process of filling and solidifying a mold cavity is accurately modeled, shrinkage cavities and other casting defects can be predicted; the effects on metal fluid flow and solidification of changing the gating/risering method or many other process variable can be simulated; and molten metal trial iterations can be significantly reduced and used primarily for concept validation.
Signals from nozzle and cavity transducers combine to generate a single, rather than a double, process variable which automatically controls any pressure changes (injection, pack or hold) to maintain a static IMP.

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