If the actuating means is manual, the control system carries the designation aquot;Haquot; for all symbols. An example is ... The use of readily recognized self-defining chemical symbols as CO2, 02. etc., falls in this same category. An alternative ... The letter aquot;Eaquot; should be used as a first letter only where the process variable is electrical.
|Title||:||Encyclopedia of engineering signs and symbols|
|Author||:||David D. Polon|