Aoniuba Flow Meter Discussion Thread
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Everyone, I’m facing a problem now and would like to discuss it with you. Use differential pressure to measure flow at the same pressure tapping point. 1. The values of the two gauges are displayed on the PLC side; the value of gauge A is several hundred units higher than that of gauge B under standard conditions. 2. Even after replacing gauge A, its value remained high. 3. After the replacement, the differential pressure percentage at the field side remained the same, but the current reading of gauge A was 2 mA higher than that of gauge B as measured at the cabinet side. 4. When the gauges were separated and current values were supplied directly to both of them, the PLC displayed the same flow rate. 5. Check that both the range and set value are correct. If there are any other things that have been overlooked, please let me know, guys. Thank you. If there are any new updates, they will be shared promptly
It seems that the two are quite close to each other; have you tried swapping the signal wires of the two tables to see what happens? If Table A still shows a higher value, then there is still a difference in the instrument itself; could it be an issue with the grounding of the enclosure?
If the decision table is correct, is it because one of the tables has its values squared while the other one does not?
The big boss is right; both meters have had their values squared on the PLC side, and meter A was squared again at the site. Previously on-site it was said to be linear and that the gauge was fine; I didn’t expect this, so they checked it again and found that this gauge had its value squared :Q
This is a fairly common issue; generally, the display on-site shows no problems, but there are issues with the output, and this is usually caused by settings in the transmitter
By switching the display mode on-site, the issue with taking square roots should become apparent
It’s probably due to the effect of circuit current, or it could indeed be a differential pressure issue. I’ve encountered situations where the water flow rate into a boiler was measured using two orifice plates, with one giving a higher reading and the other a lower one; it turned out that the difference in differential pressure was to blame. Resistance during pressure measurement in the pressure conduits, as well as differences in diameter, can cause inaccurate differential pressures. Additionally, when selecting orifice plates for low-pressure applications, I do not recommend using any products other than those from Rotam.