Low-flow resection problem
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I have a question for everyone regarding low-flow cutoff: what is the difference between zero-point cutoff and linear cutoff in low-flow cutoff? What occasions are they used for respectively?
Low-flow trimming is a method used when the flow rate in a pipeline is below the normal measurement range, or when the pipeline is shut down due to interference; in such cases, there is a slight differential pressure. By taking the square root of this value, it is possible to make the DCS display a flow rate. However, if this approach is used in material balance calculations, it can cause problems for the process control system. Linear trimming is the first method that comes to mind in such situations
“\"Zero-cutting\": when the flow rate is below the cutting point, the value is set to zero； “\"Linear cutting\": when the flow rate is below the cutting point, it is handled according to a linear relationship. When the flow rate is below the range within which accurate measurement is possible, the meter’s performance deteriorates (including its resistance to interference), resulting in large measurement errors; this issue is usually addressed by using a low-flow cutoff mechanism that eliminates readings at zero flow ； In some flowmeters, the relationship between flow rate and the value detected by the sensor is nonlinear within the normal measurement range, while it becomes linear when the flow rate is below that range (turbine flowmeters are an example of this), and in such cases the term “linear cutoff” is used.
“When below the normal measurement range, the flow rate is in a linear relationship with the value detected by the sensor (this is the case for turbine flowmeters, for example). The sentence above is complete nonsense. The sentence upstairs is complete nonsense. The sentence upstairs is complete nonsense. Upstairs, they’re talking nonsense. Important things should be said three times to convey half the meaning. :P