Range of pulse signal
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The mass flow measurement range of ABB is 0–16,000 kg/h; it outputs pulse signals with a pulse equivalent of 60. What value in hertz should be set for the range during configuration? It uses the DCS from Zhejiang University’s Control System Department; a pulse equivalent of 1000Hz is set to 60, and the display range is 60,000. So can it correspond to 16,000 kg/h? How did everyone set it up?
The two ranges do not match; the frequency range of the flow meter is around 266 Hz. 60 pulses/kg × 16000 kg/h = 960000 pulses/h, which equals 266.666 Hz. It would be better to set the flow meter’s range to 18000, as this makes calculations easier. I’m not sure if this calculation is correct; I haven’t used pulses for a long time now
Actually, the range doesn’t matter much. The measurement principle is: mass flow rate (kg/h) = number of pulses per second × pulse equivalent × 3600; it’s sufficient to count the number of pulses per second.
I saw an explanation of pulse equivalent online: the flow rate per unit time, divided by the number of pulses per unit time, gives the pulse equivalent. The unit is KG/P. For the calibration of flowmeters, the value given is P/KG; I believe this represents the instrument coefficient. I’m not sure if it’s correct?
For EMERSON’s flow meters, I set the range to 50400 KG/HR with a frequency of 7 Hz; 50400 KG/HR ÷ (7 * 3600) = 2 KG/PULES