Interface level measurement by using level troll
There are two methods of interface level measurement with level troll
a) using service fluids (both)
b) using the water
a) Using the service fluids
First of all the the level troll is 100% filled with the liquid having low specific gravity.
Then out put of transmitter is set to 0% (4ma/3 psig).
After that the level troll is 100% filled with the liquid having heavier specific gravity and the out put of transmitter is set to 100% (20ma/15psig)
By this transmitter would measure the interface level
b) using the water
In this method level calculation is made as follows
Water level for low density liquid= S.G of liquid*total height of level troll
Fill up the level troll about the level obtained by the formula then set the out put of transmitter for 0% (4ma/3psig)
After that obtain the level of water for the high density liquid
After level for high density liquid= S.G of liquid*total height of level troll
Fill up the level troll about the level obtained by formula and set the transmitter out put for 100 %( 20ma/15psig)