Rotary flow meter
Thread Content
The range of the rotameter is 40–100 kg/h; does this correspond to 4–20? If so, if the DCS range is set to 40-100, will it keep displaying 40 if there is no measurement?
4ma should correspond to 0, right? If the flow meter reading is less than 40, the measurement may be inaccurate; it doesn’t necessarily show 0.
Setting 4mA to 0 is incorrect, right?； Is it set up this way at the site? If so, has it been verified to find out what the transmitter current is when the flow rate at the site shows 40? How to set it up requires consulting the manufacturer, or you can find out by testing the transmission current yourself
This post was last edited by Qiushui Han Guang on 2023-1-29 at 08:39. The flow measurement range of the rotor is 40–100 kg/h, but the actual measurement range of the instrument is 0–100 kg/h; the corresponding current signal ranges from 4 to 20. Rotary flowmeters have relatively poor accuracy; their typical range ratio is 1:10. Therefore, the values 40-100 marked on the instrument’s scale indicate that accuracy cannot be guaranteed below 40. However, the scale corresponding to 4M mHA is still 0kg/H, so the DCS range should be set to 0-100. If it is set to 40-100, this will cause a mismatch between the on-site scale and the DCS display; in that case, if no value is available, 40 will be displayed continuously.