PID diagram
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What is the logic of the instruments inside the circle in the image? Temperature, pressure, and flow rate are all connected together; please, experts, show yourselves quickly
This post was last edited by ylb913 on 2018-7-27 at 13:39. This flow meter features temperature and pressure compensation. To correct the effects of pressure and temperature changes on flow measurement.
Do you mean that it is combined with temperature and pressure for the compensation of the instrument?
Pressure and temperature compensation adjusts the flow rate, which is very common in PID controllers.
It’s not simply about combining flow rate, pressure, and temperature on-site. Instead, the pressure and temperature values are fed into the DCS, where a calculation formula is used to automatically correct any deviations in the flow rate readings that result from the pressure or temperature deviating from the design values.
The process depends on mass flow rate, rather than volume flow rate. During on-site binding, an orifice plate used to measure volumetric flow rate is paired with a differential pressure transmitter; thus, the measured volumetric flow rate is sent to the DCS for temperature and pressure compensation. In other words, the density under actual operating conditions is calculated based on the actual pressure and temperature, thereby yielding the mass flow rate. The tag number is enclosed in a square frame with a horizontal line running through the center; it represents a soft point within the DCS (that is, a functional soft module)
I’ve learned it now; before, I saw that other manufacturers did the calculations manually