Reasons for the sudden negative value of the instantaneous flow rate in the Instromet ultrasonic flow meter
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When the Instromet ultrasonic flow meter is operating normally, the instantaneous flow rate suddenly becomes negative for about several dozen seconds before returning to normal. Could someone please explain this? Thank you. As shown in the figure
1. Intermittent neuropathy episodes 2. Intermittent neuropathy episodes 3. Intermittent neuropathy episodes 4. I’ve racked my brains but can think of no other reasons. Thank you.
If the medium is a liquid, there may be a phenomenon of incomplete filling of the tube or backflow; if it is a gas, backflow may occur~~
What is the installation method – clamping or plug-in?
It's difficult to judge this situation. . There are too many possibilities, and the conditions are limited, making it impossible to rule them all out one by one. Watch the excitement
Question: Why does the flow rate reading turn negative when the pipe is under pressure? ,,,, Why? Is there a theoretical basis? . . . . .
The principle of ultrasonic flowmeters: if it occurs suddenly, it is possible that an abnormality in the material is to blame
Ultrasonic flowmeters that use the time difference method measure the difference between the time it takes for sound to travel in the forward direction and the time it takes to travel in the reverse direction; the flow velocity is then calculated from this value. When bubbles are present, due to the different sound speeds in various media, it is possible for the time required for sound to travel in the reverse direction to be shorter than that in the forward direction, resulting in a negative value. This is just my personal understanding… haha. Please forgive any mistakes~~
Ultrasonic flowmeters that use the time difference method measure the difference between the time it takes for sound to travel in the forward direction and the time it takes to travel in the reverse direction; the flow velocity is then calculated from this value. When bubbles are present, due to the different sound speeds in various media, it is possible for the time required for sound to travel in the reverse direction to be shorter than that in the forward direction, resulting in a negative value. This is just my personal understanding… haha. Please forgive any mistakes~~
The medium is natural gas. The flow rate data shown in the two images above was recorded over a period of 1 minute; it’s clear that this flow rate is not related to pressure, as the gas is transported through pipelines where the pressure remains very stable