How are the high and low reports determined in a DCS system? Is it based on experience?
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How are the high and low reports determined in a DCS system? Is it based on experience? For example, the normal liquid level is 40–60%; a low alarm is triggered at 30% and a high alarm at 70%
Determined by safety or production process requirements
There are no relevant regulations; is it sufficient as long as the manufacturing process or safety standards are met?
The settings of flammable and toxic detectors can be used as a reference; if it comes to reaction parameters, these are determined based on the characteristics of the raw materials and the reaction conditions. Generally, an alarm is triggered when the value exceeds the reaction threshold, while an elevated alarm is issued when the value exceeds that threshold by 15% or 20% (as long as it does not exceed the safety threshold).
It is determined based on the process requirements: for example, feeding is required when the level is below 40%, the pump must be stopped when it is below 30%, feeding should be halted when the level exceeds 70%; at even higher levels, there may be problems with the feeding mechanism. All these aspects are specified by the process requirements
There must be requirements; the range that cannot be set is quite limited. It seems there are rules specifying how much time is available for handling things after an alarm is triggered