I need help regarding which books to refer and some useful sites wherein i could get some information about WLC's. wold be really grateful to you guys if you could help me out.

 

I could use some more info. Ultrasonics such as Milltronics work well in Water Treatment, but gas in produced water in Oilfield makes them unstable.
In that application a large diaphram pressure such as Majorguage does very well.

 

"www.almegcontrols.com/":http://www.almegcontrols.com/ or - how to control a level picture. This could be either float, continuous, 4-20 etc.

"www.almegcontrols.com/controlling_a_level.htm":http://www.almegcontrols.com/controlling_a_level.htm
Thanks Bob

 

Radar may also be a good alternative. Suggest the gas density/vapor change is what is making the ultrasonics unstable. Radar should not be effective. Milltronics makes radar as do other folks. Don't know what $$ your pain level is at, but radars are available for under $2K. E&H, ThermoMeasureTech, Ohmart/Vega are folks to look at.

 

this is a good option in Ultrasonic Analog Distance check this.
"http://www.iprocessmart.com/electrical/idec_sa6a.htm":http://www.iprocessmart.com/electrical/idec_sa6a.htm