Why does the flow meter show values when there is no medium?
Thread Content
In manufacturing processes, it is common for some flow meters to display relatively high values even when no fluid is flowing through them. Could experts help analyze what are the typical reasons for this phenomenon?
Possible causes: 1. Excessive or incorrect positive and negative migration of the transmitter; 2. Blockage in one of the pressure tapping tubes, resulting in a pressure difference; 3. Leakage of the isolation fluid inside the pressure tapping tubes
When the electromagnetic flowmeter is in an empty-tube state, it operates at its maximum capacity. This is a problem with the table itself. . . . . . . .
In addition to the reasons mentioned by the friends upstairs, some flow meters (such as differential pressure flow meters) exhibit large errors at low signal levels, which is why they are not used. Due to issues with the transmitter itself – where the output does not reach exactly zero at the zero point, even within the allowable error range – zero-point drift can still result in a flow reading being displayed. Therefore, it is necessary to implement a mechanism for filtering out low-level signals when using such flow meters.
Air traffic control, vibration frequency interference, small-signal rejection methods, identification of non-full-tank conditions, and so on
This post was last edited by tonyblue on 2012-6-30 at 17:14. Some applications require temperature and pressure compensation; although there is no actual flow rate or pressure difference, temperature is still present, so values will still be generated. You can use a manual controller to eliminate low-level signals. Generally, a low cutoff value should be used for zeroing, as errors increase when the signal level is low due to the square root operation
I’m a bit worried about the electricity meter and water meter at my home. . . . . . . . .
It depends on the type of flow meter being used for analysis; flow meters based on orifice plates, electromagnetic principles, vortex shedding, electric target technology, mass flow meters, and so on, all have different measurement principles, and the reasons for similar problems vary accordingly. It’s not difficult to understand this when considering the methods and principles of measurement.
Comrades on the 7th floor, don’t worry – the principle of water meters is sufficient to ensure their working accuracy at low flow rates!
1. Differential pressure flow meters: in most cases, it is due to an imbalance in the static pressures in the positive and negative pressure tubes； 2、Significant zero-point drift ； 3. The positive and negative diaphragms of the transmitter are deformed and do not return to their original position ； 4. There is a problem with the transmitter’s power conversion section; the value is above 4MA!
It’s possible that the extreme heat causes the residual medium in the pipelines to evaporate, resulting in uneven pressure distribution on the surface; this in turn can lead to problems with the pressure transmission lines