Issues regarding the use of differential pressure transmitters for measuring density
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As the title suggests, how does a differential pressure transmitter measure the density of a liquid? How is its range calibrated? What are its installation requirements? Hope someone with more experience can give some advice
If you really want to use this to measure density, it is recommended that you install it vertically, as density = P/9.8H
The measurement method is similar to that used for measuring the liquid level in sealed, pressurized containers with differential pressure transducers, but it is necessary to ensure that the opening of the negative pressure tube of the equipment is always below the liquid surface. 2. Range = difference in height between the two openings × (maximum density – minimum density) × acceleration due to gravity. 3. It is preferable for the transmitter to be at the same height as the device opening of the positive pressure pipe ； If it is not possible to ensure that the negative-pressure tube is always filled with a low-density medium, then it is advisable to install a separation tank and fill it with a separating fluid. 4. The amount of migration is given by: {（height of the liquid column in the positive-pressure tube × density of the medium in the positive-pressure tube × acceleration due to gravity） + (difference in heights of the openings × minimum density × acceleration due to gravity)} – {（height of the liquid column in the negative-pressure tube × density of the medium in the negative-pressure tube × acceleration due to gravity)}. The result obtained is usually negative, indicating negative migration. The units mentioned above are: mm, Kg/m3, m/s^2, Pa. Increasing the height difference between the two openings can improve the measurement accuracy, but it is necessary to ensure the correct position of the opening in the negative pressure tube.
I’ve saved it; I’ll take the time to study it properly later. This is very useful; thank you
The measured height must remain constant, and the level of the liquid medium must always be greater than or equal to that height
It’s like the measurement interface of a transmitter, utilizing a “constant” density difference. Now it’s the other way around: testing density in reverse. @jiaguoyun