Double-flange differential pressure transmitter’s
Thread Content
Can a secondary instrument be installed above the two flanges, and will that have any impact on the measurements?
This post was last edited by waneng on 2017-4-21 at 12:30. The secondary instrument you mentioned should refer to a transmitter unit; a double-flange transmitter with a capillary for remote transmission can be installed above the two flanges. In principle, such installation is not recommended, unless there is no suitable operating platform or for other reasons. Remember to set it to zero!
Theoretically, the installation height of the transmitter does not affect the measurements. I once heard a foreign expert say that the transmitter should not be higher than the flange on the negative pressure side. Why is that? He can’t explain it either. Dual-flange level transmitters are preferably not used for level measurement in negative pressure systems.
When the transmitter is positioned above the negative pressure measurement flange, the absence of fluid under negative pressure causes the pressure in the capillary to act in the \"opposite direction\" on the negative pressure diaphragm; over time, this can have a \"vacuuming\" effect on the diaphragm. With a positive-pressure flanged diaphragm, the medium pressure constantly acts on the diaphragm, so there is no issue with positive pressure.
I only know that the one on-site is called a primary meter; I’ve never heard of a secondary meter.
I don’t understand what kind of meter the original poster is referring to with the term “secondary meter”