Measuring Tank Levels with Radar - Limitations

Yes, it worked reasonably OK but you cannot set it up and forget about it. We were using transmitters of suitable IP rating (66 I think) and were mounted in a standoff cone welded to top of tank, then connected some pressurised plant air to the side of the transmitter end of the cone. This allowed some cooling and positive pressure purging of the cone which helped to keep dust buildup away. Its not perfect but probably once a week we had to lift the radar transmitter from cone and clean by hand, then bung it back on. Addition of some teflon spray on the unit helped to keep it from buildups. Your air supply must be filtered so it stayed DRY.

Rok

Though air radar is a very good choice for applications which will clog or heavily coat contact level measument probes. When I worked at Magnetrol, one of our early through air radar application was heated road tar in an outdoor tank and that is very, very sticky.

Radar is not always the best solutions for some application. Radar could suffer from loss of signal faults if the application has excessive foam or false level faults if the tank sides, supports and ladders become heavily incrusted with tank material.

You should talk with your though air radar manufacture application engineer about your situation.

Check out this article and possibly the supplier.

http://www.powderandbulk.com/pb_services/news_center/publish/article_001192.shtml

Is continuously-weighing the tank out of the question?

In the coastal grain elevator we had 3 different kinds of level indicators that I knew of. one had a slow [8 rpm?] rotating paddle at the top and when the paddle stop and slipped it would trigger alarm. mostly foolproof. for bin bottoms there was an electrical or magnetic rod on a chain and every once in awhile the chain would have to banged or shook but mostly trouble free for years.

For continous product height in the shipping bins a contractor installed sonar which eventually became quite reliable. don't know the name. because of cone shape of product piling between the 4 of them a you fairly good idea of how much was in a bin. updated every second. could even be used on an angle from the top. Contractor came from Seattle, USA.