Can Level Gauge (Reflex Type) with Transmitter be combined?

[Ulon]

Hi all,

I always come across integrated Level Gauge (magnetic type) with Transmitter (usually magnetostrictive) in market.

Some times, we cannot use magnetic type of Level Gauge thus selecting option of reflex type or trasnparent type (genrally known as Flat Glass Level Gauge).

Has anybody see an integrated system of Level Gauge & Level Transmitter according to the title above.

 

[JLSeagull]

The magnetic gauges with magnetostrictive or guided wave radar provide visible and remote measurement. In my perfect world I would never see another gauge glass assembly.

I have seen some of the tubular gauge glasses with an alarm contact but not a flat gauge glass. Check with Joggler or other tubular glass manufacturers to see if they have an alarm devide that can accommodate a flat glass. I don't think that you will find a suitable transmitter.

 

[ilan7]

Use the reflex level gage and install next to it a level transmitter. (I prefer the DP transmitter with two seals and capillary tube). This way you have two instruments and if one fail, the other still works. I do not think that buying an gage with transmitter is cheaper then the two seperate instruments. Do not think there is a Reflex type with a transmitter, only with optical switches.

 

[Ulon]

Thanks guys,

I just want to confirm it before making decision to saperate it.

Well, I'm thinking of using The Reflex Level Gauge with Guided Wave radar type of Level Transmitter. Since my application density is varied in some range. Any comment on this?

 

[JimCasey]

If you use a reflex gage in that application it should be the pad-mounted type. Not an external chamber.

Since you have variable SG it is possible for different SG to exist in the external chamber than in the actual vessel, so the reading will be off. It can be WAAAY off if you have interface of 2 fluids.

With the pad mount, you just have a window into the vessesl and the gage will see the same surface the GWR beamsees.

 

[JLSeagull]

Did I mention that I don't like gauge glasses?

With a pad mount, when it is damaged either mechanically or by the fluid, you must take the vessel out of service. This is rarely convenient unless the unit has parallel trains of equipment with surplus capacity.

BTW there is a second order thing (one of those calculus things, I don't even remember what that means) happening with any external level device if the vessel diameter is small as compared to the external chamber. Picture a vessel and external displacer chamber with the same diameter. A pulsating pressure could force liquid from the vessel into the chamber and back in an oscillation where the actual and measured level are 180 degrees out of phase. This is rarely the case except in R&D plants.