DP transmitter level indicator question

[frankiee]

Hi
this is an instrumentation and control question
A given tank has hot water process fluid in the bottom and steam as a gas on top.
It has a differential pressure transmiter level with the bottom of the tank
It has a wet leg on the low side of the d\p to control the steam condensate.
If the system was filled with heavy water (sp 1.1) originally and then the whole system was changed to normal light water (sp=1)
What would happen to the level indication if the tank had the same level with both waters?

thanks

 

[gmax137]

It will read low with the light water, right? Unless you re-calibrate it when you change the density of the water.

 

[frankiee]

I don't know the answer but I was thinking it would read high
The DP wet leg would be biased out with the heavy water.
The heavy water would be replaced with lighter water and the dp cell would see more of a delta P. and therefore read more on the gauge then what the tank level really was.
I don't know the answer.
I don't know how they bias the wet leg out so I can't picture it.