![]() These sometimes need moderate-to-high gain and less integral. For the latter, a characterization is more subtle – you want to characterize the slope of the PV for various OPs instead of its value. For others (such as level) the direction (slope rather than value) of the PV is relative to the OP. ![]() These should be characterized as shown above – they typically need more integral and minimal P-gain. Generally these PVs begin to show the result of an OP change immediately (even if the time constant to complete the change is long) and do not need any derivative.Īnother categorization of PVs: some (such as flow) increase when the OP increases and decrease when the OP decreases. These tend to have a significant delay between a change in OP and the beginning of the change in PV (#2 above), and therefore might benefit from derivative action.īulk properties describe the state of the fluid as a whole so that it all changes everywhere in a pipe or vessel (for practical purposes) simultaneously. ![]() ![]() Particle properties include temperature, pH, conductivity, etc. Particle properties are those where a fluid in a pipe may have different properties in different areas, so that the fluid must be mixed or moved to change the property at the PV measurement point. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |