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When a DP transmitter is hooked up to a pressurized closed vessel, it must compensate for the gas pressure pushing down on top of the liquid. instart instrumentation course ch 5 leve link
Level Link systems typically operate using displacement or differential pressure principles. In displacement systems, a float or displacer moves with the liquid level. This movement is linked to a transmitter that converts physical motion into an electronic signal. Differential pressure systems measure the weight of the liquid column. The "Link" refers to the mechanical or digital connection between the sensing element and the control system. : When a DP transmitter is hooked up
Common in wet leg setups where the reference column exerts a higher pressure on the low side than an empty tank exerts on the high side. The negative offset must be shifted up ("elevated") to properly align the 4mA signal with an empty vessel. 5. Mechanical and Advanced Continuous Level Instruments This movement is linked to a transmitter that