The traffic accumulation values differ between the field and the DCS
Thread Content
There is an orifice plate flow meter; the flow accumulation values displayed by the on-site flow accumulator and those on the DCS differ for the same time period, although the instantaneous flow rates are the same. It’s not clear which side is having the problem. Seeking advice from experts. (The flow integrator uses German-made components, and the DCS is PCS7.) ）
Check whether the ranges on both sides are the same, and whether there is any low-frequency signal rejection or anything like that
The measurement of orifice plate flow meters is carried out using a differential pressure transmitter. Generally, its range is related to the pressure difference; it does not directly display the flow rate. However, some manufacturers may include a calculation module in the field transmitter, but the various parameters used in such calculations can differ from those used in actual computations – factors such as square roots, fluid diameter ratios, and viscosity coefficients come into play. There is also the issue of whether the output is in cubic units or tons. Even when these conditions are met, the measurement accuracy of orifice plate flow meters drops below 30 percent; at lower flow rates, a small-signal cutoff mechanism is necessary, typically set at 3 to 5 percent
Check whether the flow accumulation period on the on-site flow meter is consistent with that on the DCS
LZ might want to consider the number of pulses. Is the decrease in output pulses caused by wear and tear from the use of the instrument? The key is whether to conduct on-site verification