LydiaMiller
Industrial
- Mar 10, 2015
- 5
thread698-348788
I wanted to reply to an old post where vjaksic81 was having some measurement problems with a Rosemount 5300 Guided Wave Radar. I work for Emerson Process Management on their Rosemount Level products, which includes the 5300. The vapors in this application, diesel vapor, would be negligible for the radar measurement. And a Dynamic Vapor Compensation (DVC) probe would not be recommended for this type of application as no compensation would be needed.
The tape method you are using for measurement I believe is actually getting different reading due to the way it is measuring. It could be that that the metal plate at the bottom that you are measuring from may be moving due to the weight of the liquid on top of it. This would be consistent with the readings between the radar and the tape. The plate would move further with more liquid and less with less liquid. But these plates are typically well fixed at the bottom, so that may not be the cause at all. But what does happen with tanks is that they will change shape due to temperature changes, the weight of the contents, etc. This can affect the distance between the plate at the bottom and the nozzle at the top. The tape measurement is made from the bottom up – so it is measuring the liquid level from the bottom plate. The radar measurement, on the other hand, is measuring from the nozzle at the top to the level of the liquid. Additionally, you are measuring at two different points in the tank, so the tank movements could be different from one location to the next.
The radar should give you consistent measurements, as it seems to be now. They will just not correspond directly to the level measurements you get from the tape. But you will need to determine how the radar levels relate to the volume as they will not be that same as for the tape.
I wanted to reply to an old post where vjaksic81 was having some measurement problems with a Rosemount 5300 Guided Wave Radar. I work for Emerson Process Management on their Rosemount Level products, which includes the 5300. The vapors in this application, diesel vapor, would be negligible for the radar measurement. And a Dynamic Vapor Compensation (DVC) probe would not be recommended for this type of application as no compensation would be needed.
The tape method you are using for measurement I believe is actually getting different reading due to the way it is measuring. It could be that that the metal plate at the bottom that you are measuring from may be moving due to the weight of the liquid on top of it. This would be consistent with the readings between the radar and the tape. The plate would move further with more liquid and less with less liquid. But these plates are typically well fixed at the bottom, so that may not be the cause at all. But what does happen with tanks is that they will change shape due to temperature changes, the weight of the contents, etc. This can affect the distance between the plate at the bottom and the nozzle at the top. The tape measurement is made from the bottom up – so it is measuring the liquid level from the bottom plate. The radar measurement, on the other hand, is measuring from the nozzle at the top to the level of the liquid. Additionally, you are measuring at two different points in the tank, so the tank movements could be different from one location to the next.
The radar should give you consistent measurements, as it seems to be now. They will just not correspond directly to the level measurements you get from the tape. But you will need to determine how the radar levels relate to the volume as they will not be that same as for the tape.
