Mass flow meter

It depends on what type of mass flow meter it is – thermal or Coriolis. Thermal flow meters can measure very small flow rates as well as low-speed flows. Whether to perform resection depends on your actual needs; I have used both thermal and cryo methods without ever resorting to resection.

Mass flow meters generally have a measurement range as well as a range within which accuracy can be guaranteed. For example, if the measurement range is 0–10 m3/h, the range within which accuracy can be ensured might be 0.5–10 m3/h. When the flow rate is below 0.5 m3/h, it’s no longer possible to guarantee accurate measurements. Lower flow rates result in smaller volumes of flow. It’s advisable to ask the manufacturer about the range within which accuracy is guaranteed, and to check whether the pipe diameter is suitable. When the flow rate is too low, signal suppression is necessary, as this could be due to valve leakage or an inability to close the valve properly. If the flow rate is too low even under normal operation, then there is a problem with the choice of flow meter, and the issue of signal suppression becomes irrelevant

I’ve learned about it; the factory just installed a thermal type of unit, and I still don’t understand how it works. It looks similar to a transmitter and also has a display screen. I’m not sure how to maintain it Is a hand controller used too?

I’ve never used a controller with a Coriolis mass flow meter, but one should be available; there are setting buttons on the panel. When installing it, first ensure that the pipe is full; second, keep it away from sources of vibration – the pipe itself shouldn’t vibrate too much, otherwise it needs to be reinforced; third, pay attention to the differences in installation methods for measuring liquids versus gases.

In the case of Coriolis systems, when the flow rate is low or the operating density is low, the accuracy decreases. There is a option for small cuts in the table header. @jiaguoyun

The Coriolis flow meter is suitable for media with high viscosity and low flow rates, offering a measurement accuracy of +/-0.1 of the measured value. Small-signal clipping can be performed; it is recommended to set the clipping level at 0.5~1% of the upper measurement limit~~

Microwave solid flow meters can be considered

Flowmeters generally maintain accuracy within their measurement range; accuracy outside this range cannot be guaranteed. Small-signal rejection is typically used in the presence of interference

I’m not sure which manufacturer’s mass flow meter is being used, but generally speaking, the approach to solving this problem is as follows: First, obtain a calculation sheet from the manufacturer; if that’s possible, then your problem will be resolved, as the calculation sheet includes error curves； Secondly, if it cannot be obtained, then one should look at the maximum flow rate; manufacturers that are of decent quality can achieve an accuracy error of within 0.5% at flow rates above 1% of the maximum flow rate ； Finally, the key, the crucial point of this issue is the zero-point fluctuation ； In other words, no matter how good the instrument is, if its zero point cannot be guaranteed after installation, it cannot be used for low flow rates. Therefore, selection and theoretical calculations are one aspect, while process and installation conditions are extremely crucial. As for small-signal rejection, you need to consult a professional manufacturer for an explanation; small-signal rejection does not affect accuracy. Based on this, a resection volume of over 1% is unreasonable; it should be within 0.5%.